Talk:Cancer/Archive 6

This is an archive of past discussions about Cancer. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page.

Archive 1

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Archive 4

Archive 5

Archive 6

Archive 7

What links here

I think it would be good to look at what redirects here. There are several things that redirect here but aren't mentioned in the text, and probably should be (cancerophobia would be easy to fit in, I think). There are a couple that should probably be repointed, and at least one ("AKKK") that I have no idea what it means. Is anyone else able to help with this? WhatamIdoing (talk) 00:29, 27 August 2013 (UTC)

Height and cancer risk

Apparently a large study found a correlation in women: . Worth mentioning in the article? -- Beland (talk) 21:47, 2 September 2013 (UTC)

Yes have seen that one. Would be good to have a secondary source. Doc James (talk · contribs · email) (if I write on your page reply on mine) 01:12, 11 September 2013 (UTC)

What counts as being cancer

http://well.blogs.nytimes.com/2013/07/29/report-suggests-sweeping-changes-to-cancer-detection-and-treatment/ has an interesting (to me, anyway) overview of the debate about whether some of the borderline neoplasias ought to be called "cancer" or not. I think it might be interesting to include just a sentence or two about the possibility of some "cancers" being renamed (essentially to "precancer" or the equivalent, like what used to be called early-stage cervical cancer was renamed cervical intraepithelial neoplasia a while ago). Has anyone else seen any other sources on this? WhatamIdoing (talk) 20:35, 1 September 2013 (UTC)

It's a good question, for which I have no immediate answer. I'll see if I can't come up with some sound sources. There is no sharp demarcation, and it is a moving target. The ACS has not counted non-melanoma skin cancers in its annual cancer incidence for ages. Renal cell carcinomas under 2cm used to be called renal tubular adenomas. Many gynecological neoplasms are described as "low malignant potential". They may undergo malignant transformation in which they become invasive, but they can also kill by mass effect without tissue invasion. I'll look into this, but my time will be limited in the next week. If you see nothing from me in about ten days (and no one has beaten me to the punch), please do something to get me refocused.Novangelis (talk) 04:21, 3 September 2013 (UTC)

Hardly definitive, but here's a nice description: "indolentomas". Again, I'll focus, soon.Novangelis (talk) 23:15, 3 September 2013 (UTC)

I've never seen that name, but I like it. Remember that WP:there is no deadline. If we get to this soon, that's great. If we get to it later, then that's great, too. WhatamIdoing (talk) 03:46, 4 September 2013 (UTC)

I found my old notes on the subject. They are only 14 years out of date, now, in addition to being original research. It would be nice to put a definition of cancer at the top of the page, and the gray zone at the boundaries of the definition would fit in. While there is no time limit, this is a timely subject which should be addressable without engaging in WP:RECENTISM. I'm going to hit the textbooks and see what they say. I'll try to write something and the one word on my mind is "continuum".Novangelis (talk) 00:51, 11 September 2013 (UTC)

Yes will look at clarifying. We have neoplasms (which are the same as tumors) and can be benign or malignant. The malignant version of neoplasms / tumors are cancers. But some people say benign cancers (or at least I used to before I learned this distinction). Doc James (talk · contribs · email) (if I write on your page reply on mine) 01:03, 11 September 2013 (UTC)

I threw together a potential nidus for a "Definitions" section. Among other things, I'll track down the untransliterated Greek for karkinos tomorrow unless someone has a source at their fingertips.Novangelis (talk) 03:16, 11 September 2013 (UTC)

Wiktionary says that it's καρκίνος. WhatamIdoing (talk) 04:03, 11 September 2013 (UTC)

Much of it was already in the history section. Doc James (talk · contribs · email) (if I write on your page reply on mine) 04:06, 11 September 2013 (UTC)

Rearranging

Doc James, I don't understand why you moved that new subsection. It's about what happens at diagnosis. So why would you put that in ==Signs and symptoms==? Crying for a week after you've been diagnosed with cancer is neither a medical sign nor a symptom of cancer. WhatamIdoing (talk) 04:50, 11 September 2013 (UTC)

Depression / psychological effects of cancer would be a symptom in some people. The risk of suicide is not just an issue at diagnosis but persists after diagnosis. Depression can also occur due to losing previous abilities due to advancing disease. Do not mind if you move it back but IMO it fits well here. Doc James (talk · contribs · email) (if I write on your page reply on mine) 04:57, 11 September 2013 (UTC)

Depression and/or anxiety could be a symptom that the patient experiences, but being depressed or anxious because of receiving a cancer diagnosis is not a symptom of cancer. In some cases, it's a symptom of adjustment disorders or PTSD or similar mental health problems, but it's not a symptom of the cancer itself (unlike pre-diagnosis depression, which can be).

The purpose of the symptoms section is to identify the symptoms and signs that suggest someone has a given disease, not to list every symptom that might be associated with its entire existence. We wouldn't list "missing an arm or leg" as a medical sign for osteosarcoma, even though amputations are a medical sign that results from osteosarcoma. Similarly, I don't think that we should put the results of diagnosis into the list of things that suggest a need for the diagnosis.

The recommended order for sections is fundamentally chronological: What are the symptoms, how is the diagnosis made, what's the treatment, what's the prognosis. Putting issues that are purely post-diagnosis back into the pre-diagnosis section doesn't make sense chronologically. WhatamIdoing (talk) 05:56, 11 September 2013 (UTC)

With the better sourcing, this is out of place in a section called "Signs and symptoms". Watching for signs of depression after diagnosis is like watching for fever after chemo: neither tells you about the disease itself. There are some sources that discuss depression as a direct symptom (example), but sorting physiological fatigue from depression is problematic.

The workaround is renaming the section to something like "Preliminary diagnosis" which would include both the presentation and the consequences of the diagnosis.Novangelis (talk) 06:24, 11 September 2013 (UTC)

Moved back. Doc James (talk · contribs · email) (if I write on your page reply on mine) 15:38, 11 September 2013 (UTC)

European Code against cancer

Not sure how notable this is but it might be suitable to include in the article. It is a list of 11 key preventative things that people can do to prevent cancer. I think it has come from the EU. Lesion (talk) 19:46, 2 November 2013 (UTC)

Minor edit - stress should not be listed as a cause of cancer

Under 'Causes', second sentence, "stress" should not be listed as a cause of cancer. Most major cancer organisations (Cancer Research UK, American Cancer Society, Cancer Council Australia, etc) have made public statements saying that stress is not a known cause of cancer, with the American Cancer Society stating categorically that "No scientific evidence has shown that a person’s personality or outlook can affect their cancer risk". It's a minor edit, but kind of important.

http://www.cancer.org/cancer/cancerbasics/questions-people-ask-about-cancer http://www.cancerresearchuk.org/cancer-info/healthyliving/cancercontroversies/stress/ — Preceding unsigned comment added by 115.186.229.220 (talk) 05:58, 29 November 2013 (UTC)

"Carcinogen" not mentioned in the lede

Close discussion caused by time-wasting blocked Sockpuppeteer ChrisfromHouston I just now noticed that the term carcinogen is never mentioned in the lede. The word first appears about ten paragraphs into the body. I think the term is important enough, and used widely enough, to warrant being placed somewhere in the lede.
I've been criticized for alphabet waterboarding of sorts, so I will leave it to another editor who agrees with this suggestion to perform that surgery.--ChrisfromHouston (talk) 13:17, 20 December 2013 (UTC)

(Unqualified) use of tobacco increases the risk of cancer?!

More information Close discussion caused by time-wasting blocked Sockpuppeteer User:ChrisfromHouston ...

Close discussion caused by time-wasting blocked Sockpuppeteer User:ChrisfromHouston

The following discussion has been closed. Please do not modify it.

Quoting the lede:
"Many things are known to increase the risk of cancer, including tobacco use..."

This as a patently unfounded statement. What the science clearly shows is that habitual tobacco use causes an increased risk of cancer. My efforts to fix the article have repeatedly been reverted, so raising the issue here for the purpose of consensus. I realize this is an emotional issue, but an encyclopedia is supposed to communicate straight facts. For the time being the statement in question is being flagged with a {{Citation needed}} tag.

If the fact of the matter is that reliable sources say that smoking one cigar per month will increase cancer risk, then that would support the statement as is. But my understanding is that the standard definition of "smoker" for scientific studies is a person who smokes every day. We have data on addicts. Casual and infrequent use, not so much. (I'm actually not aware of any conclusive data.)--ChrisfromHouston (talk) 12:17, 4 November 2013 (UTC)

I don't see a huge problem with the current wording. On other articles like basal cell carcinoma we might say sunlight exposure increases the risk. Of course it is assumed that if someone exposed their skin to sunlight for only 1 min per day there would negligible risk (of BCC anyway). To qualify the statement that there is no known lower limit of increased risk (or whatever the correct statistical babble is) is too complex for the lead, which is supposed to be clear and concise (WP:LEAD). This does not necessarily rule out this point being made elsewhere in the article, perhaps where smoking is discussed. Please use a WP:MEDRS source for this if you do. Thanks, Lesion (talk) 12:45, 4 November 2013 (UTC)

Agree with Lesion. Our readers are smart. They can use some common sense. Doc James (talk · contribs · email) (if I write on your page reply on mine) 12:16, 5 November 2013 (UTC)

@Lesion- I don't get your point regarding that skin cancer article at all. Practically everyone is exposed to sunlight. An exact quote from that article is, "Sunlight is a factor in about two-thirds of these cancers...". And that is not a statement presented in the lede.

Now look at the Actinic keratosis article. Here you have an article that states up front in the second sentence of the lede, "...it is associated with those who are frequently exposed to the sun, as it is usually accompanied by solar damage."

That is an example of a well-written lede statement. This cancer article here would be presenting much more accurate info if it stated that 'smoking damage' is what is actually linked to increased cancer risk, not simply exposing oneself to smoking.--ChrisfromHouston (talk) 08:20, 6 November 2013 (UTC)

@Doc James- I totally disagree with a view that sloppy and inaccurate statements should be accepted because readers are intelligent enough to figure out what part of what we write is accurate versus the part we write that is garbage. It is our job as editors to present to readers the highest quality statement (which form the highest quality articles) that we can put together.--ChrisfromHouston (talk) 08:20, 6 November 2013 (UTC)

If you want to say "smoking daily increases the risk of cancer, but smoking once in a while does nothing" then use a WP:MEDRS source please. Furthermore, as I suggested above, it is enough detail for the lead to say that smoking increases the risk, and then go into more details in the body of the article if needed. Lesion (talk) 08:23, 6 November 2013 (UTC)

Having being involved in oropharyngeal cancer research in the past, I must say that I remember something about a very minimal level of smoking being enough to initiate field change in mucosal surfaces. However, it is known that in oropharyngeal cancer, most risk comes from heavy smoking and drinking in combination. Lesion (talk) 08:31, 6 November 2013 (UTC)

Chris you do not have consensus. That smoking causes cancer is one of the best pieces of epidemiological / toxicological evidence in existence. Doc James (talk · contribs · email) (if I write on your page reply on mine) 11:41, 6 November 2013 (UTC)

This edit was pointy and thus I reverted it Doc James (talk · contribs · email) (if I write on your page reply on mine) 11:44, 6 November 2013 (UTC)

By the way we could make these excessive explanations for all the factures (certain infections could be certain infections after being present for many years) etc. But we can just state the facts. Doc James (talk · contribs · email) (if I write on your page reply on mine) 11:48, 6 November 2013 (UTC)

Didn't the link between smoking and lung cancer fundamentally change epidemiology? See Bradford Hill criteria. Lesion (talk) 12:42, 6 November 2013 (UTC)

Yes.

Also, I believe that "habitual use" and "addiction" are technically separate concepts.

I don't think we need to get into minor details here. The same complaints could be made about every item in the list: overeating one day or getting one dental X-ray will not have a significant effect on cancer risk, either. WhatamIdoing (talk) 22:12, 6 November 2013 (UTC)

If one wished to be picky, one could argue that it should probably read "...including exposure to tobacco smoke..." It is not only users of tobacco that are put at risk of cancer. AndyTheGrump (talk) 22:26, 6 November 2013 (UTC)

Chewing tobacco causes oral cancer. Doc James (talk · contribs · email) (if I write on your page reply on mine) 09:53, 7 November 2013 (UTC)

Agree with Andy's point to cover "second hand smoking". Technically, exposure (of oneself) covers chewing tobacco too. Lesion (talk) 09:56, 7 November 2013 (UTC)

Okay yes agree we could change it to "tobacco exposure". Doc James (talk · contribs · email) (if I write on your page reply on mine) 10:15, 7 November 2013 (UTC)

WhatamIdoing had made an excellent point in that the critique that I had highlighted actually applies across the board. But instead of taking an attitude that this can't be fixed, and isn't important enough to be fixed, I will suggest that there is an easy and painless fix to help get the article to conform to accurate facts. Here is a proposed change that may be seen as satisfactory to everyone here:

"Many things at a sufficient level are known to increase the risk of cancer, including exposure to tobacco use, dietary factors, certain infections, exposure to radiation, lack of physical activity, obesity, and environmental pollutants."

Any objection? Notice that it includes a correction for tobacco that will now cover 2nd hand smoke as well as chewing tobacco, per the discussion above.--ChrisfromHouston (talk) 21:53, 6 December 2013 (UTC) [Dec19 edit: bolding, to help prevent people from missing what the proposal is actually saying.]

Oppose as it is perfectly clear as it is. Doc James (talk · contribs · email) (if I write on your page reply on mine) 05:51, 7 December 2013 (UTC)

Yes, it is perfectly clear. The problem, however, is that it is perfectly inaccurate.

The proposed change is both: perfectly clear and perfectly accurate.

Surely there are editors here who care about Wikipedia communicating accurate info, instead of making garbage statements because we do not care enough to be accurate with what we put into our articles.

The other point, clearly asserted above, is that the current statement fails to indicate that it is not necessary to be a tobacco user in order to have your cancer risk increased. It can be sufficient to merely be in the proximity of smokers. The proposed change does an accurate job of covering that as well.--ChrisfromHouston (talk) 09:20, 18 December 2013 (UTC)

I think that what you want is overly precise for what's supposed to be a simple summary. And even what you've written can be nitpicked to death: what if my "use" of tobacco is as a decorative item in the garden? Am I, and anyone who walks past my garden, going to have a higher risk of cancer because we were all "exposed" to a "use" of tobacco?

The lead is supposed to be a simple summary in plain English. The other details belong elsewhere on the page. WhatamIdoing (talk) 00:02, 19 December 2013 (UTC)

I don't see anything fancy or convoluted or detailed or overly precise in the proposed change. The clear and simple answer to your tobacco garden is covered by the simple qualifier: "at a sufficient level". Very simple. And even better, it is simple and accurate.

Compare that to how the article reads now - simple and wrong.--ChrisfromHouston (talk) 11:00, 19 December 2013 (UTC)

Could it be original research to change this wording based upon an editor stating there is a lack of evidence for increased risk of carcinogenesis from occasional smoking? If we had a source which said exactly this wording, it would be fine... but I suspect most of our sources use the wording we do currently. Lesion (talk) 11:09, 19 December 2013 (UTC)

Here... I will turn this around to make the exact inaccuracy more clear to you:

Fact: Smoking one single cigar constitutes use of tobacco.

Now look at what the article says: "Many things are known to increase the risk of cancer, including tobacco use..."

This is a totally false statement. There is absolutely no evidence produced by anyone that smoking one cigar (here, an example of tobacco use) will increase anyone's risk of cancer. Unless anyone can provide a reliable source to support such a conclusion - which everyone here knows we can't - then our imperative is to DELETE a statement that communicates false information.

The alternative being offered is to replace the false statement with the accurate one proposed. Delete, or fix. Those are the only two tenable alternatives that I see here. As for what the scientific studies actually state, I expect that if you were to read them you will find that their terms are well defined. I seem to remember having made this point early on in this section - that a "smoker" is typically defined by such studies as a person who smokes daily. That is what I clearly remember from reports I have read in years past.--ChrisfromHouston (talk) 11:26, 19 December 2013 (UTC)

Here, I went and dug up one example: http://cancercontrol.cancer.gov/brp/tcrb/monographs/9/m9_1.pdf.

On pdf pg6of20, Table 1 shows the categorization that was used in their study. The lightest column that qualified as a smoker is "Cigars per day: 1-2 cigars" or "Cigarettes per day: <1 pack".

So if you smoke 19 cigarettes each and every single day, then you are pushed off to the left of the very lightest level of smoking that they categorize. The comparison to a non-smoker is a person who smokes zero cigars and zero cigarettes every decade (read: nothing). I have looked at many such reports, and this categorization is typical. If you smoke six cigars per week - one each and every day, but skip Sundays - then they won't look at you. Your level of smoking does not count for what they're studying. You could even smoke three packs a day, and if you're taking that one day off, then they still won't take you into their study. You aren't smoking often enough for them.

The gem is on pg8:

Risks among occasional cigar smokers are difficult to measure because of the wide variability in frequency of smoking among occasional cigar smokers and the marked variation in the amounts of tobacco contained in different cigars.

What it is saying is that they don't have a clue.--ChrisfromHouston (talk) 12:10, 19 December 2013 (UTC)

Not exactly. Doc James (talk · contribs · email) (if I write on your page reply on mine) 17:54, 19 December 2013 (UTC)

(edit conflict) It's more complicated than that. Smoking one cigar, or going out in the sunshine one time, could actually cause cancer. You would have to be appallingly unlucky, but it's biologically possible to get cancer from an allegedly "safe" exposure.

Radiation is simpler to explain: Radiation causes cancer because it hits exactly the wrong spot at exactly the wrong moment. The spots and moments are so rare that if you're trying to induce cancer deliberately, you'd want to hit a billion spots. However, you could get cancer from just one single ray—if it happened to land on exactly the wrong spot at exactly the wrong moment (which it is extremely unlikely to do).

When you look at studies like these, they're comparing groups with arbitrary cutoffs. The cutoffs are not magic. Six cigars a week is not magically safe merely because some researcher decided to put you in the "low exposure" group. Did you look at the results for those "low exposure" groups? If you did, then you'll notice that some of them ended up with lung cancer, too. Look at this review: The line in there about "no evidence of a threshold" is statistician-speak for "even smoking one cigarette every now and again can cause lung cancer". WhatamIdoing (talk) 18:07, 19 December 2013 (UTC)

And guess what... not smoking at all, and not ever being exposed to smoke in your entire life you can still get lung cancer. I hope everyone here is clear that the issue being discussed is tobacco exposure causing increased risk.

The two of you cannot provide any reliable source that concludes that smoking one cigarette in your entire life will create an increased risk, because no such study has ever been published. Congratulations, you've dived into the deep end of fear mongering, at the expense of valid science and simple logic.--ChrisfromHouston (talk) 21:22, 19 December 2013 (UTC) [edit: CORRECTED--ChrisfromHouston (talk) 22:09, 19 December 2013 (UTC)]

Reply, Take 2...

I would like to reply to the quote from that study from a different angle. Here is the exact statement in full:

"There is a dose-response relationship for cigarette smoking and lung cancer, with no evidence of a threshold."

The point I would like to highlight is that what they are saying is exactly the same thing as what I had said earlier above. What this statement says is NOT "there is no threshold". It is saying we have no clue.

The key point is that these two statements:

"no evidence of a threshold", and

"evidence of no threshold"

...are two VERY DIFFERENT STATEMENTS. WhatamIdoing, you are presenting the quote as saying the latter, and the application of simple logic makes it clear that it does not say this. You position is unsupported. It cannot be supported (for reasons detailed in the explanation just posted below).--ChrisfromHouston (talk) 23:16, 19 December 2013 (UTC)

There is a very simple reason why science, as it stands today, is incapable of providing such precision: They simply do not have a methodology to provide such accuracy.

Their data is heavily polluted by factors such as bias, confounding and simple self-reporting errors. Accurate studies could be done. It would require scientists to treat human beings like caged lab rats. They could pump a very specific level of smoke into a very controlled environment such as a prison. Using a methodology like this would make a lot of progress toward finding what the actual threshold is. But this will never be done in the USA. It will never be done by any country that has the capability of producing accurate scientific results. And the reason there is obvious: Because the methodology is constrained by what is ethical.

We can imagine a future where fully functional human lungs will be grown in a petri dish. Where batteries of such lungs will be exposed to ever diminishing levels of smoke in an extremely well controlled environment. And the data will be compared to the cancer rate found in an exactly identical colony of fabricated human lungs. THEN, it will be possible to ethically and accurately find the exact threshold where smoking exposure creates an increased risk of cancer. Only then.

And after we've stretched our imaginations to this sci-fi limit, we are faced with stretching our imaginations even more to try to think of who would pay for such a study and why. The intelligence level of such a future society can be imagined to be quite content with the science that was produced in the 1960s: excessive smoking will lead to an increased risk of cancer.--ChrisfromHouston (talk) 21:57, 19 December 2013 (UTC)

Ok, in light of everything presented above, I will repost the proposed change here:

"Many things at a sufficient level are known to increase the risk of cancer, including exposure to tobacco use, dietary factors, certain infections, exposure to radiation, lack of physical activity, obesity, and environmental pollutants."

Does anybody have an objection they'd like to maintain? And if so, can the aggregate of objections possibly constitute a consensus that this proposed change would not be an improvement to the article?

The statement is clear, simple, easy to understand ...and accurate.--ChrisfromHouston (talk) 23:28, 19 December 2013 (UTC)

The current statement is clearer and more to the point. I oppose this change. Doc James (talk · contribs · email) (if I write on your page reply on mine) 00:08, 20 December 2013 (UTC)

Oppose suggested change as well. Current prose represents the sourcing accurately and is economical and straightforward enough for a lead. Proposed change is rather tortured prose and unnecessarily pedantic. The proposed qualifiers are unnecessary--just like if you had "Foods with high glycemic index numbers make blood sugar levels rise quickly" it wouldn't be necessary to write "Foods with high glycemic index numbers when eaten in sufficient quantities make blood sugar levels rise quickly": it obscures the point, and a reader with common sense isn't going to think that the former sentence means that if you eat 0.5 g of russet potato your blood sugar is going to rise 100 points in five minutes. And considering the review article WhatamIdoing found, the proposed qualifiers are entirely unnecessary. Zad68 02:01, 20 December 2013 (UTC)

If you had been following this from the beginning, you would know that my original edit from October was the insertion of a single word. Absolutely nothing tortured about it. It was from the later effort to accommodate the subsequent rash of "lawyering" that led to the present proposal. I actually agree with your criticism of it being "tortured".

Seeing how the vast majority of research data pertains to daily use, the original edit seems to be the best way to correct sloppy info from the article to what is unquestionably accurate. Given the totality of arguments presented here over the past 7+ weeks, this would appear to be the best supported change. I've just now made that edit. It is a perfectly accurate statement that is extremely well supported by many, many medical studies.--ChrisfromHouston (talk) 04:27, 21 December 2013 (UTC)

Chris, AFAICT everyone opposes your desired change. I oppose your sloppy conflation of habitual use and addiction (which is especially ironic, since you claim to be making it "unquestionably accurate"), and I oppose your effort to push the POV that only high levels of tobacco use cause cancer. You've not proven your case to the satisfaction of any other editor. We're not asking you to agree that the article is correct, but at this point—and unless and until you can find any other editor to support your change—I believe that you need to drop the WP:STICK and give up. WhatamIdoing (talk) 23:42, 21 December 2013 (UTC)

Where did I ever say that "only high levels of tobacco use cause cancer"?!

I have never even stated (best I recall) that the most minute level of smoking or exposure to smoke is safe. What I've been stressing is that such data is not available. Comprende? The point was, and is, regarding presenting facts that can be supported by reliable sources.

"Tobacco use (unqualified) increases the risk of cancer" - Totally unsupportable.

"Habitual tobacco use increases the risk of cancer" <<< THIS is the fact that is backed up by reliable sources, with many many studies.

So how does having the word habitual linking to the article addiction constitute "sloppy conflation" on my part? Are you trying to tell me that you don't believe that nicotine is addictive? Or if you're clear it's additive, are you saying that habitual use of an addictive drug is irrelevant to addiction? Either such view is clearly mistaken. So why the pointed criticism about me tying these two highly relevant concepts? Is there a reason why you'd rather have them firewalled? Well how difficult would it be to change it to [[addiction|addiction]] or [[habit|habitual]]? Radical solution. And would that actually be an improvement? My edit called attention to both issues in the space of a single word. And both issues are central when it comes to the connection between cancer and tobacco.

Your revert has returned the article to the state of communicating inaccurate, unsupportable info. Over the past seven weeks here I have worked diligently toward building consensus, taking into account all valid criticisms. And then I get scoffed and mocked.

This is not a WP:DEADHORSE issue. The horse is quite alive and kicking. The issue is that you all are calling the horse a mule, when that fact is only HALF RIGHT. There is only one half of the "tobacco use increases cancer risk" statement that can be supported. And that's the right side of the spectrum of usage levels where we have accurate scientific data.

The primary policy issue I see to apply here is WP:UNDUE. You all are putting undue weight on the left half of that spectrum. The guidance is clear:

"...in determining proper weight, we consider a viewpoint's prevalence in reliable sources, not its prevalence among Wikipedia editors or the general public."

The overwhelming prevalence of reliable sources with the scientific studies supports the edit I have been promoting. You could take a vote here and it turns out 99-to-Me, and in the absence of sources supporting the 99, Wikipedia lets us know that your declaration of the horse being dead is invalid. I'll wrap this up in a sound bite, for anyone who may want to cut to the quick here...

"It's the sources, not the horses." - Wikipedia Policy, paraphrased

This is my grounds for re-revert. Anyone who would like their objection to hold will need to back up such a position with reliable support. And even then, DUE WEIGHT still tells us that we need to go with the prevalence.--ChrisfromHouston (talk) 11:26, 22 December 2013 (UTC)

Hello Chris, I think you are making edits against strong consensus. You may feel that your version is closer to the trust than the one endorsed by other editors, but in the end consensus typically carries the day. You could try Wikipedia's dispute resolution process, but as a lone voice you are not likely to find support for your view.

For what it's worth, your version totally ignores the dangers of secondary exposure. In many countries without laws that promote smoke-free working environments, people are routinely exposed to tobacco smoke from others. How is that "habitual" or "addiction"? What you are looking for is a word that clearly states that the risk of cancer has a relationship with the amount of exposure (heavier smokers have a higher risk) but even so there is obvious evidence that even light smokers are at an increased risk.

I would strongly encourage you to find common ground with the other editors. You may need to concede defeat. JFW | T@lk 13:44, 22 December 2013 (UTC)

Unambiguous policy states that Wikipedia is WP:Not_A_Democracy. If one editor provides reliable sources to support one view, and a thousand editors post their view backed up by ZERO such sources, Wikipedia policy gives clear guidance on proper action: Have the article change to reflect what the weight of the sources can support. I'll put this one into sound bite form too...

"One source is worth a thousand editors voting 'oppose'." - Wikipedia Policy, paraphrased

If you can't back up your position with reliable sources, then you have no ground to stand on. My grounds for reverting today are the same as before. As for your other points, you've jumped into an issue here that has spanned three months. You might want to catch up on important discussion you've missed, particularly the proposal posted in bold, not too far above. If you have any open questions or comments after getting up to speed, I'd be glad to discuss them with you. But if I were to simply rehash issues for anyone who didn't want to take the time to get acquainted what's been going on here, then I would not see that to be an efficient use of time or words.

As for any ideas you may have for improving the statement, I'd be glad to see that.--ChrisfromHouston (talk) 09:23, 24 December 2013 (UTC)

Close

Thermography

Advantages of thermography[edit]

It shows a visual picture so temperatures over a large area can be compared
It is capable of catching moving targets in real time
It is able to find deteriorating, i.e., higher temperature components prior to their failure
It can be used to measure or observe in areas inaccessible or hazardous for other methods
It is a non-destructive test method
It can be used to find defects in shafts, pipes, and other metal or plastic parts[5]
It can be used to detect objects in dark areas
It has some medical application, essentially in kinesiotherapy

...........................................................................

It is a non-destructive test method

http://en.wikipedia.org/wiki/Thermography#Advantages_of_thermography

176.24.38.232 (talk) 00:54, 15 February 2014 (UTC)

This article is about cancer. We need high quality sources. Doc James (talk · contribs · email) (if I write on your page reply on mine) 01:04, 15 February 2014 (UTC)

Primary sourced content

I've just removed a large amount of primary-sourced content from the Epigenetics section. I have copied it here in case anyone can find anything useful. Sunrise (talk) 07:56, 8 March 2014 (UTC)

More information Extended content ...

Extended content

[Sporadic cancers] For example, when 113 colorectal cancers were examined in sequence, only four had a missense mutation in the DNA repair gene MGMT, while the majority had reduced MGMT expression due to methylation of the MGMT promoter region (an epigenetic alteration).^[1] Five different studies found that between 40% and 90% of colorectal cancers have reduced MGMT expression due to methylation of the MGMT promoter region.^[2]^[3]^[4]^[5]^[6]

Similarly, out of 119 cases of mismatch repair-deficient colorectal cancers that lacked DNA repair gene PMS2 expression, PMS2 was deficient in 6 due to mutations in the PMS2 gene, while in 103 cases PMS2 expression was deficient because its pairing partner MLH1 was repressed due to promoter methylation (PMS2 protein is unstable in the absence of MLH1).^[7] In the other 10 cases, loss of PMS2 expression was likely due to epigenetic overexpression of the microRNA, miR-155, which down-regulates MLH1.^[8]

In further examples, tabulated in the article Epigenetics, epigenetic defects were found at frequencies of between 13%-100% for the DNA repair genes BRCA1, WRN, FANCB, FANCF, MGMT, MLH1, MSH2, MSH4, ERCC1, XPF, NEIL1 and ATM in cancers including those in breast, ovarian, colorectal, and head and neck. In particular, two or more epigenetic deficiencies in expression of ERCC1, XPF and/or PMS2 occurred simultaneously in the majority of the 49 colon cancers evaluated by Facista et al.^[9]

[Heavy metals] For example, one group of studies shows that arsenic inhibits the DNA repair genes PARP, XRCC1, Ligase III, Ligase IV, DNA POLB, XRCC4, DNA PKCS, TOPO2B, OGG1, ERCC1, XPF, XPB, XPC, XPE and P53.^[10]^[11]^[12]^[13]^[14]^[15] Another group of studies shows that cadmium inhibits the DNA repair genes MSH2, ERCC1, XRCC1, OGG1, MSH6, DNA-PK, XPD and XPC.^[16]^[17]^[18]^[19]^[20]

[Colon cancer] Colon cancers were also found to have an average of 17 duplicated segments of chromosomes, 28 deleted segments of chromosomes and up to 10 translocations.^[21] However, by comparison, epigenetic alterations appear to be more frequent in colon cancers. There are large numbers of hypermethylated genes in colon cancer, as discussed above.^[22]

[miRNAs] For instance, epigenetic increase in CpG island methylation of the DNA sequence encoding miR-137 reduces its expression and is a frequent early epigenetic event in colorectal carcinogenesis, occurring in 81% of colon cancers and in 14% of the normal appearing colonic mucosa adjacent to the cancers. Silencing of miR-137 can affect expression of over 400 genes, the targets of this miRNA.^[23] Changes in the level of miR-137 expression cause altered mRNA expression of the target genes by 2 to 20-fold and corresponding, though often smaller, changes in expression of the protein products of the genes. Other microRNAs, with likely comparable numbers of target genes, are even more frequently epigenetically altered in colonic field defects and in the colon cancers that arise from them. These include miR-124a, miR-34b/c and miR-342 which are silenced by CpG island methylation of their encoding DNA sequences in primary tumors at rates of 99%, 93% and 86%, respectively, and in the adjacent normal appearing mucosa at rates of 59%, 26% and 56%, respectively.^[24]^[25] Thus, epigenetic alterations are a major source of changes in gene expression, important in cancer.

[1]
Halford S, Rowan A, Sawyer E, Talbot I, Tomlinson I (June 2005). "O(6)-methylguanine methyltransferase in colorectal cancers: detection of mutations, loss of expression, and weak association with G:C>A:T transitions". Gut. 54 (6): 797–802. doi:10.1136/gut.2004.059535. PMC 1774551. PMID 15888787.{{cite journal}}: CS1 maint: multiple names: authors list (link)
[2]
Shen, L; Kondo, Y; Rosner, GL; Xiao, L; Hernandez, NS; Vilaythong, J; Houlihan, PS; Krouse, RS; Prasad, AR; Einspahr, JG; Buckmeier, J; Alberts, DS; Hamilton, SR; Issa, JP (2005). "MGMT promoter methylation and field defect in sporadic colorectal cancer". Journal of the National Cancer Institute. 97 (18): 1330–8. doi:10.1093/jnci/dji275. PMID 16174854.
[3]
Psofaki, V; Kalogera, C; Tzambouras, N; Stephanou, D; Tsianos, E; Seferiadis, K; Kolios, G (2010). "Promoter methylation status of hMLH1, MGMT, and CDKN2A/p16 in colorectal adenomas". World journal of gastroenterology : WJG. 16 (28): 3553–60. doi:10.3748/wjg.v16.i28.3553. PMC 2909555. PMID 20653064.{{cite journal}}: CS1 maint: unflagged free DOI (link)
[4]
Lee, KH; Lee, JS; Nam, JH; Choi, C; Lee, MC; Park, CS; Juhng, SW; Lee, JH (2011). "Promoter methylation status of hMLH1, hMSH2, and MGMT genes in colorectal cancer associated with adenoma-carcinoma sequence". Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie. 396 (7): 1017–26. doi:10.1007/s00423-011-0812-9. PMID 21706233.
[5]
Amatu, A; Sartore-Bianchi, A; Moutinho, C; Belotti, A; Bencardino, K; Chirico, G; Cassingena, A; Rusconi, F; Esposito, A; Nichelatti, M; Esteller, M; Siena, S (2013). "Promoter CpG island hypermethylation of the DNA repair enzyme MGMT predicts clinical response to dacarbazine in a phase II study for metastatic colorectal cancer". Clinical cancer research : an official journal of the American Association for Cancer Research. 19 (8): 2265–72. doi:10.1158/1078-0432.CCR-12-3518. PMID 23422094.
[6]
Mokarram, P; Zamani, M; Kavousipour, S; Naghibalhossaini, F; Irajie, C; Moradi Sarabi, M; Hosseini, SV (2013). "Different patterns of DNA methylation of the two distinct O6-methylguanine-DNA methyltransferase (O6-MGMT) promoter regions in colorectal cancer". Molecular biology reports. 40 (5): 3851–7. doi:10.1007/s11033-012-2465-3. PMID 23271133.
[7]
Truninger, K; Menigatti, M; Luz, J; Russell, A; Haider, R; Gebbers, JO; Bannwart, F; Yurtsever, H; Neuweiler, J; Riehle, HM; Cattaruzza, MS; Heinimann, K; Schär, P; Jiricny, J; Marra, G (2005). "Immunohistochemical analysis reveals high frequency of PMS2 defects in colorectal cancer". Gastroenterology. 128 (5): 1160–71. doi:10.1053/j.gastro.2005.01.056. PMID 15887099.
[8]
Valeri, N; Gasparini, P; Fabbri, M; Braconi, C; Veronese, A; Lovat, F; Adair, B; Vannini, I; Fanini, F; Bottoni, A; Costinean, S; Sandhu, SK; Nuovo, GJ; Alder, H; Gafa, R; Calore, F; Ferracin, M; Lanza, G; Volinia, S; Negrini, M; McIlhatton, MA; Amadori, D; Fishel, R; Croce, CM (2010). "Modulation of mismatch repair and genomic stability by miR-155". Proceedings of the National Academy of Sciences of the United States of America. 107 (15): 6982–7. doi:10.1073/pnas.1002472107. PMC 2872463. PMID 20351277.
[9]
Facista, A; Nguyen, H; Lewis, C; Prasad, AR; Ramsey, L; Zaitlin, B; Nfonsam, V; Krouse, RS; Bernstein, H; Payne, CM; Stern, S; Oatman, N; Banerjee, B; Bernstein, C (2012). "Deficient expression of DNA repair enzymes in early progression to sporadic colon cancer". Genome integrity. 3 (1): 3. doi:10.1186/2041-9414-3-3. PMC 3351028. PMID 22494821.{{cite journal}}: CS1 maint: unflagged free DOI (link)
[10]
Roy, M; Sinha, D; Mukherjee, S; Biswas, J (2011). "Curcumin prevents DNA damage and enhances the repair potential in a chronically arsenic-exposed human population in West Bengal, India". European journal of cancer prevention : the official journal of the European Cancer Prevention Organisation (ECP). 20 (2): 123–31. doi:10.1097/CEJ.0b013e328341017a. PMID 21332098.
[11]
Qin, XJ; Liu, W; Li, YN; Sun, X; Hai, CX; Hudson, LG; Liu, KJ (2012). "Poly(ADP-ribose) polymerase-1 inhibition by arsenite promotes the survival of cells with unrepaired DNA lesions induced by UV exposure". Toxicological sciences : an official journal of the Society of Toxicology. 127 (1): 120–9. doi:10.1093/toxsci/kfs099. PMC 3327874. PMID 22387748.
[12]
Ebert, F; Weiss, A; Bültemeyer, M; Hamann, I; Hartwig, A; Schwerdtle, T (2011). "Arsenicals affect base excision repair by several mechanisms". Mutation research. 715 (1–2): 32–41. doi:10.1016/j.mrfmmm.2011.07.004. PMID 21782832.
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Andrew, AS; Karagas, MR; Hamilton, JW (2003). "Decreased DNA repair gene expression among individuals exposed to arsenic in United States drinking water". International Journal of Cancer. Journal International Du Cancer. 104 (3): 263–8. doi:10.1002/ijc.10968. PMID 12569548.
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Nollen, M; Ebert, F; Moser, J; Mullenders, LH; Hartwig, A; Schwerdtle, T (2009). "Impact of arsenic on nucleotide excision repair: XPC function, protein level, and gene expression". Molecular nutrition & food research. 53 (5): 572–82. doi:10.1002/mnfr.200800480. PMID 19382146.
[15]
Shen, S; Lee, J; Weinfeld, M; Le, XC (2008). "Attenuation of DNA damage-induced p53 expression by arsenic: A possible mechanism for arsenic co-carcinogenesis". Molecular carcinogenesis. 47 (7): 508–18. doi:10.1002/mc.20406. PMID 18085531.
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Zhou, ZH; Lei, YX; Wang, CX (2012). "Analysis of aberrant methylation in DNA repair genes during malignant transformation of human bronchial epithelial cells induced by cadmium". Toxicological sciences : an official journal of the Society of Toxicology. 125 (2): 412–7. doi:10.1093/toxsci/kfr320. PMID 22112500.
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Wieland, M; Levin, MK; Hingorani, KS; Biro, FN; Hingorani, MM (2009). "Mechanism of cadmium-mediated inhibition of Msh2-Msh6 function in DNA mismatch repair". Biochemistry. 48 (40): 9492–502. doi:10.1021/bi9001248. PMID 19320425.
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Bravard, A; Vacher, M; Gouget, B; Coutant, A; De Boisferon, FH; Marsin, S; Chevillard, S; Radicella, JP (2006). "Redox regulation of human OGG1 activity in response to cellular oxidative stress". Molecular and Cellular Biology. 26 (20): 7430–6. doi:10.1128/MCB.00624-06. PMC 1636869. PMID 16923968.
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Viau, M; Gastaldo, J; Bencokova, Z; Joubert, A; Foray, N (2008). "Cadmium inhibits non-homologous end-joining and over-activates the MRE11-dependent repair pathway". Mutation research. 654 (1): 13–21. doi:10.1016/j.mrgentox.2008.04.009. PMID 18539077.
[20]
Schwerdtle, T; Ebert, F; Thuy, C; Richter, C; Mullenders, LH; Hartwig, A (2010). "Genotoxicity of soluble and particulate cadmium compounds: Impact on oxidative DNA damage and nucleotide excision repair". Chemical research in toxicology. 23 (2): 432–42. doi:10.1021/tx900444w. PMID 20092276.
[21]
Muzny, Donna M.; Bainbridge, Matthew N.; Chang, Kyle; Dinh, Huyen H.; Drummond, Jennifer A.; Fowler, Gerald; Kovar, Christie L.; Lewis, Lora R.; Morgan, Margaret B.; Newsham, Irene F.; Reid, Jeffrey G.; Santibanez, Jireh; Shinbrot, Eve; Trevino, Lisa R.; Wu, Yuan-Qing; Wang, Min; Gunaratne, Preethi; Donehower, Lawrence A.; Creighton, Chad J.; Wheeler, David A.; Gibbs, Richard A.; Lawrence, Michael S.; Voet, Douglas; Jing, Rui; Cibulskis, Kristian; Sivachenko, Andrey; Stojanov, Petar; McKenna, Aaron; Lander, Eric S.; Gabriel, Stacey (2012). "Comprehensive molecular characterization of human colon and rectal cancer". Nature. 487 (7407): 330–7. doi:10.1038/nature11252. PMC 3401966. PMID 22810696. {{cite journal}}: Unknown parameter |displayauthors= ignored (|display-authors= suggested) (help)
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Balaguer F, Link A, Lozano JJ; et al. (August 2010). "Epigenetic silencing of miR-137 is an early event in colorectal carcinogenesis". Cancer Res. 70 (16): 6609–18. doi:10.1158/0008-5472.CAN-10-0622. PMC 2922409. PMID 20682795. {{cite journal}}: Explicit use of et al. in: |author= (help)CS1 maint: multiple names: authors list (link)
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Deng, G; Kakar, S; Kim, YS (2011). "MicroRNA-124a and microRNA-34b/c are frequently methylated in all histological types of colorectal cancer and polyps, and in the adjacent normal mucosa". Oncology letters. 2 (1): 175–180. doi:10.3892/ol.2010.222. PMC 3412539. PMID 22870149.
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Grady, WM; Parkin, RK; Mitchell, PS; Lee, JH; Kim, YH; Tsuchiya, KD; Washington, MK; Paraskeva, C; Willson, JK; Kaz, AM; Kroh, EM; Allen, A; Fritz, BR; Markowitz, SD; Tewari, M (2008). "Epigenetic silencing of the intronic microRNA hsa-miR-342 and its host gene EVL in colorectal cancer". Oncogene. 27 (27): 3880–8. doi:10.1038/onc.2008.10. PMID 18264139.

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Treatment versus management

IMO management is a better term when it comes to cancer as most cases of cancer are not simply treated with a 7 day course of anything. While the two terms mean more or less the same management implies greater difficulty which is the cause. Others thoughts? Doc James (talk · contribs · email) (if I write on your page reply on mine) 04:53, 14 March 2014 (UTC)

My first reaction on seeing the section was that "management" in this context is a euphemism similar to "living with," and should be replaced under WP:W2W.

I agree that it implies greater difficulty to an extent, but to me it carries a greater implication that any treatments are ineffective, which is a major problem (we need trust and compliance from patients in order to cure them, after all). For myself, that is a more important issue - as per my edit summaries, I'm fine with any number of compromises that address this (like splitting Management and Treatment into different sections) rather than being interested in making any precise distinction between the two.

In terms of definition, it seems to me that you think the term "treatment" either requires or implies that the patient is cured (or has a reasonable expectation of a cure), as in your comment above and your edit summary here - is that correct? That's contrary to my experience though - there is prophylactic treatment, chronic treatment, etc. Sunrise (talk) 07:18, 15 March 2014 (UTC)

If you wish to start a RfC regarding which to use I would have no concerns. We seem to understand the meaning of the word differently. I am against creating two sections with each term naming one. I support management, but if there is a majority that prefer treatment we can move it to that. Doc James (talk · contribs · email) (if I write on your page reply on mine) 07:26, 15 March 2014 (UTC)

I think "management" is entirely appropriate, and I agree with James that it is much better for the complex and multifacetted approach than just "treatment". A lot of cancer is "managed" by watchful waiting, and that ain't treatment. Prophylaxis is also not treatment (is a contradiction in terms). I don't see "management" as a euphemism for "living with" at all; "I'm managing" is not the same as "[my disease] is being managed". JFW | T@lk 14:47, 16 March 2014 (UTC)

I don't think that the choice is very important. Management implies a reasonably permanent need for medical attention; treatment implies that it's over and done with at some point. Some cancers (e.g., non-invasive skin cancer) is definitively treated. Others (e.g., pretty much stage 4 anything) are "managed". Probably half the cases are best described by the one term and the other half are best described by the other. As far as I'm concerned, we could flip a coin. WhatamIdoing (talk) 22:01, 16 March 2014 (UTC)

Fair enough. I won't bother taking up everyone's time with an RfC. :-) Sunrise (talk) 03:53, 20 March 2014 (UTC)

Whatever we call the section, there is nothing here on drug therapies of the various kinds covered in the sub-article Management of cancer. Johnbod (talk) 13:30, 24 April 2014 (UTC)

Malignant progression

Half of the Truth

Minor change to last paragraph of opening

Causes of cancer

The current redirect is to Carcinogenesis (viz. Cancer#Pathophysiology). I think a redirect here to Cancer#Causes would be more appropriate. 109.156.204.159 (talk) 12:59, 11 July 2014 (UTC)

Agreed. I've noted at my project that Obesity and cancer is missing, unlike baccy and alcohol. Wiki CRUK John (talk) 13:42, 11 July 2014 (UTC)

Done. 109.156.204.159 (talk) 14:38, 11 July 2014 (UTC)

Cancer#Causes

The Causes section currently begins:

Cancers are primarily an environmental disease (currently unlinked) with 90–95% of cases attributed to environmental factors and 5–10% due to genetics.

Apart from a slightly pedantic concern that this is arguably an inappropriate reflection of the source , which does not explicitly state that cancer is principally an environmental disease, I'm concerned that this important statement about cancer preventability is open to simplistic misinterpretation by many readers. To start a section on Causes, wouldn't it a good idea to explain first that cancer etiology is generally multifactorial (genetic predisposition → environmental triggers, etc)? 109.156.204.159 (talk) 14:38, 11 July 2014 (UTC)

Yes, I don't like that - and HS says "absolute rubbish". Every word in "attributed to environmental factors and 5–10% due to genetics" opens a large question this glides over. I'd just cut for now. Very obscure journal too. Wiki CRUK John (talk) 17:32, 11 July 2014 (UTC)

Yes, the source is far from ideal. When a disease can be shown to be attributable to a given risk factor in a percentage of patients, it's ok to say that the disease is due to that factor in those patients. However, the environmental disease claim is complicated ... and I'm certainly going there now (the page is protected anyway, lol). Imo, the best place to start is with the multifactorial concept, as in the CRUK vademecum. I guess this section provides a further example of the sort of key area where skilled/expert CRUK input could really help improve our medical content in a genuinely NPOV way. 109.156.204.159 (talk) 19:10, 11 July 2014 (UTC)

Comment: I think a lay wikipedian could be forgiven for suspecting a deliberate POV split between this page and Carcinogenesis:

Per Cancer#Causes, "Cancers are primarily an environmental disease"
Per Carcinogenesis#Mechanisms, "Cancer is a genetic disease".

I think this apparent contradiction needs to be addressed, perhaps starting from the parent page here. 109.156.204.159 (talk) 12:40, 13 July 2014 (UTC)

"Cancer is a genetic disease" is I think true, but will lead most lay readers to take it that this means it is inherited, rather than caused by mutations or DNA damage (naturally occurring) etc within the lifetime of the patient (I'm well out of my comfort zone here). Environmental factors cause genetic changes, which cause cancer. The "5–10% due to genetics" is all or mainly inherited genetics. No POV I think, just things that need to be explained better. Wiki CRUK John/ Johnbod (talk) 20:41, 13 July 2014 (UTC)

Yes, the two statements I bullet-pointed are not actual contradictions; those two perspectives basically correspond to two levels of study (population / cellular). Editorially, I think we need to highlight the different levels/perspectives clearly on this page by introducing the Causes section better. Then, at the population level, there's the question of what proportion of cancers globally can reasonably be attributed to environmental/lifestyle factors. Maybe we need more cautious wording there. 109.156.204.159 (talk) 22:07, 13 July 2014 (UTC)

This is a bit complicated because words have multiple meanings. What's meant to be communicated is this:

About 5–10% of cancer cases are due (i.e., exclusively due) to hereditary factors. For example, the excess ovarian and breast cancer caused by BRCA mutations falls into this group.
- Importantly, "hereditary" and "genetic" are not the same thing. Hereditary diseases are usually genetic, but genetic diseases are frequently not hereditary.
The rest are caused by non-hereditary factors.
- "Non-hereditary" is called "environmental" in much of the literature.
- This category includes:
  - "environment" in the ecological sense: skin-cancer-causing radiation from the Sun is part of our environment.
  - "environment" in the pollution sense: lung-cancer-causing smog is part of our environment.
  - "environment" in the personal lifestyle sense: what we eat and drink, and what we do during the day, is part of our environment.

I doubt that anyone really believes that this split between hereditary and non-hereditary factors is "absolute rubbish".

If you've got a better idea for how to express this concept, then I'd be happy to hear it. Perhaps it would be better to specify "hereditary genetics" or "hereditary factors" instead of the ambiguous word "genetics"? (The original addition was here.) WhatamIdoing (talk) 03:54, 14 July 2014 (UTC)

Thanks for that. Editorially, I think we need to avoid unintentionally giving the impression of a possible nature versus nurture dichotomy here. For that reason I've removed the "Cancer is a genetic disease" statement at the start of Carcinogenesis#Mechanisms; not because it's wrong per se, but because without adequate contextual explanation it can easily be misconstrued as genetic determinism. The editorial issue here is somewhat similar, imo. We need to restore/provide some sort of introduction/context to the "environmental" statement. For a start I think we could simply copyedit out the term "environmental disease", which does not appear in the cited source and is rather ambiguous (eg are we referring to some more or less authoritative list of 'environmental diseases'? [no]). Prior to that sentence, I think we need to provide a brief but properly sourced introductory explanation of the multifactorial character of cancer, reinstating the internal link to #Pathophysiology (or perhaps #Pathogenesis would be a more helpful heading there?), to help orientate the general reader. While doing this, we can mention the concepts of innate genetic predisposition and the triggering of the disease by environmental exposures (the 'Environmental epidemiology' page is the best current link I've been able to find to reference the usage here of the term environmental-exposure).

As regards the term "hereditary factors", I don't think it would be right to use that as a synonym for genetic factors, as genetic disorders can involve new mutations that are not inherited.

(On a related matter, I think PMID 24351322 might be a potentially useful source on this page, but it's behind a paywall.)
109.157.86.177 (talk) - previously 109.156.204.159 - 12:55, 14 July 2014 (UTC)

Cancer has genetic mechanisms and its causes are mostly not inherited. Doc James (talk · contribs · email) (if I write on your page reply on mine) 01:31, 15 July 2014 (UTC)

Well, sort of... You're (we're) using "causes" here in a particular epidemiological sense referring to the necessary/sufficient conditions for a disease to manifest clinically; the "genetic mechanisms" of pathogenesis obviously involve cause and effect too, though at a different level. Editorially, this parent page needs to distinguish the two levels succinctly. Imo, the start of the #Causes section is the place to do this. 109.157.86.177 (talk) 09:25, 15 July 2014 (UTC)

We're have a very similar discussion at Talk:Pancreatic_cancer#Sentence_in_lede_needs_attention_of_subject_matter_expert, where for now I have substituted "....10% of cases are linked to inherited genes." in the lead in a comparable sentence. It would be great if we could agree terminology, even cut-and-paste phrasing, to use in such recurring situations. I was just reading this morning: "Cancer is fundamentally caused by inherited (germline) and acquired (somatic) mutations in cancer-causing genes." (my links obviously),^[1] if that's any use. Wiki CRUK John (talk) 11:23, 15 July 2014 (UTC)

I'm not sure any ready-made solution on a cut-and-paste sort of basis is feasible here. Imo, as medical editors/writers we need to cultivate an awareness of how the meanings of the words and terms we read and report may vary according to the context in which they're used. And also to be aware of the sorts of difficulties (or misunderstandings) that our readers, in turn, may have in distinguishing the intended meanings of the words we use if we fail to provide the necessary context/explanation. 109.157.86.177 (talk) 12:12, 15 July 2014 (UTC)

[1]
Wolfgang, CL; Herman, JM; Laheru, DA; Klein, AP; Erdek, MA; Fishman, EK; Hruban, RH (2013 Sep). "Recent progress in pancreatic cancer". CA: a cancer journal for clinicians. 63 (5): 326. PMID 23856911. {{cite journal}}: Check date values in: |date= (help)

We have a section on pathophysiology / mechanism that deals with the mutations in DNA as steps towards cancer. The "cause" is the things that lead to these mutations. Some times they can be inherited but usually they are not. We use this sort of language in many articles, not just cancer related ones. Quotes are not needed around environmental thus removed. Doc James (talk · contribs · email) (if I write on your page reply on mine) 12:00, 15 July 2014 (UTC)

I'm not so sure about that, as the general usage of "environmental" refers to air pollution etc, not one's own smoking, obesity etc. The very stubby Environmental factor has no medical angle, while Environmental disease (virtually reference-free) starts off with a definition that appears to restrict it to diseases only caused by environmental factors (although it doesn't). Some work would give better things to link to. Wiki CRUK John (talk) 12:21, 15 July 2014 (UTC)

We describe what environmental means in the very next sentence. Have linked environmental disease but that page does need work. Doc James (talk · contribs · email) (if I write on your page reply on mine) 12:29, 15 July 2014 (UTC)

As I tried to suggest above, I think linking as environmental factors (without any scare quotes) is explanatory, in that it helps the reader understand what sorts of risk factors are being referred to. Imo, linking to the somewhat impressionistic 'Environmental disease' page doesn't really hit the mark on that one. 109.157.86.177 (talk) 13:04, 15 July 2014 (UTC)

Ok, "Environmental epidemiology|environmental factors" - but not environmental factors, yet anyway. Not sure where MOS stands on piping to something that is itself a title. Kill or cure on environmental factor? Wiki CRUK John (talk) 14:05, 15 July 2014 (UTC)

It's not that we tend to use the wrong words as such. It's that we sometimes collectively fail, imo, to clarify editorially the context in which we're using them. As on this page where we don't currently signal to the reader that the sort of thing biologists (among other people) rightly consider, on a pathogenetic level, to be "causes" are discussed further down the page (eg like this: "see #Pathophysiology"). One side effect of this habit is that we tend to get into lengthy talk-page discussions (as in "cancer"/"carcinoma", "premalignant lesions"/"malignant cells", etc) where the semantic key tends to escape us. 109.157.86.177 (talk) 12:51, 15 July 2014 (UTC)

It's very tricky. That's why I actually favour little standard bits one can slot into the many articles where the issues occur, varying as necessary. For cancers there are a fair number - eg in all the ones I've seen familiarity with the basic processes of histology/pathology is assumed, and in many staging also. Short plain explanations would be widely applicable. Wiki CRUK John (talk) 14:05, 15 July 2014 (UTC)

I can see where you're coming from. Perhaps as in this? I thought of suggesting a similar solution in the lead on the 'Lung cancer' page (primarily edited by Axl). But when I looked at how the detail of how that is currently worded I didn't feel so confident that linking "types" like that would actually be an improvement. 109.157.86.177 (talk) 15:18, 15 July 2014 (UTC)

In "Lung cancer", I wouldn't object to "The main histopathological types". Axl ¤ [Talk] 17:03, 15 July 2014 (UTC)

More information broadly related content ...

broadly related content

While we're all here, looking at Environmental epidemiology, which I'm not sure wouldn't be better merged into E disease, is the use of "distal" like this actually correct (I mean it's clearly unneccessary, but isn't it just wrong)? "Environmental exposures can be broadly categorized into those that are proximate (e.g. directly leading to a health condition), including chemicals, physical agents, and microbiological pathogens, and those that are more distal, such as social conditions, climate change, and other broad-scale environmental changes. Proximate exposures occur through air, food, water, and skin contact. Distal exposures cause adverse health conditions directly by altering proximate exposures, and indirectly through changes in ecosystems and other support systems for human health. As usual with WP, pull on any piece of wool, and ..... Wiki CRUK John (talk) 14:11, 15 July 2014 (UTC)

I think that's basically ok actually (though the wording could be improved). Scarcely Dog and Duck stuff perhaps, but it's a broad distinction between more or less remote forms of exposure (ie potential causal determinants ) that seems to be used in the epidemiological literature (eg ) pretty much in the sense referred to on that page. 109.157.86.177 (talk) 15:01, 15 July 2014 (UTC)

Thanks, Yes, I found , which can be used to ref that passage. It seems an entirely regrettable, because unneeded, usage to me. And distal needs changing to reflect it. Wiki CRUK John (talk) 15:06, 15 July 2014 (UTC)

Yup, like it or not, every scientific sub/speciality tends to develop its own particular terminology to refer to or formalize very specific concepts. And that almost inevitably tends to hamper communication among different disciplines. Overcoming those barriers is part of the role of good science writers who are able to bring together and explain highly specialized concepts in ways that can be digested either by the broader scientific community, or (as on the present page) by the general public. 109.157.86.177 (talk) 15:51, 15 July 2014 (UTC)

- RE "distal needs changing": You mean the redirect I suppose? Anatomical terms of location#Proximal and distal seems just fine... within the context of anatomy where the term originated . 109.157.86.177 (talk) 16:07, 15 July 2014 (UTC)

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Arbitrary break - Etiology vs. Pathogenesis?

I guess the general problem might stem from an understandable reluctance to use a difficult term like "Etiology" as a heading, per normal review-writing practice. For the general Wikipedia reader we prefer the simpler word, "Causes". But "causes" isn't an actual synonym for "etiology". So, if we want to use the heading in that sense (as James at least seems to suggest here), I think we need to show what we're doing to the reader. Perhaps by using a standardized template (broadly per John's suggestion?) with an internal link to the "Pathophysiology" section.

Small note: Having said all that, I have to say the distinction made between the "Causes" and "Pathophysiology"/"Mechanism" sections in MEDMOS doesn't appear altogether clear-cut. As written, the "Causes" section invites content on "genetics" etc which may regard either pathogenesis or etiology.
109.157.86.177 (talk) 12:50, 16 July 2014 (UTC)

Yes we use causes and etiology as synonymous per using simple language. Simple language I agree is not perfect and cannot be made perfect. It is a trade off.

Genetics that is inherited would be part of "causes" while genetic changes that occur as part of the mechanisms of development would be part of the pathophysiology IMO. Doc James (talk · contribs · email) (if I write on your page reply on mine) 20:55, 16 July 2014 (UTC)

Characteristics/Hallmarks of cancer

Split off causes

This article is about 10,000 words, which is the very upper end of WP:SIZE. It's so long that it's unlikely that anyone will read it in one sitting.

The longest sections are ==Causes== and ==Pathophysiology== (which is also very technical). Would anyone mind if we split off ==Causes== (leaving behind a four- or five-paragraph summary, including a list of the main categories of causes)? It could go in Causes of cancer (currently redirecting here) and also acquire the redirect Cause of cancer that is currently pointing at Carcinogenesis.

I think this would be a fairly quick change to make. I'd like to do something similar for the path section, but I think that would be more complicated. WhatamIdoing (talk) 20:12, 15 July 2014 (UTC)

I would be more in favor of splitting of pathophysiology / simplifying the pathophysiology section. IMO our readers have greater interest in causes than pathophysiology. Doc James (talk · contribs · email) (if I write on your page reply on mine) 20:20, 15 July 2014 (UTC)

Support WAID's proposal. I think it could be good to elicit input also from WikiProjects Genetics/MCB at least. From their points of view, much of the Pathophysiology section is almost certainly discussing "causes" too. Imo, just linking internally between the two sections (nothing dramatic there surely?) would help clarify our editorial approach.

Agree with WAID we also really can do with a separate 'Causes of Cancer' page anyway. ~~Imo, that could (and probably should) cover perspectives both at the epidemiological (primary prevention) and pathogenetic (primary/secondary prevention) levels.~~If we wanted to restrict the 'Causes of Cancer' page to etiology rather than pathogenesis , I think we could perhaps do this by means of an appropriate dab header referring the reader to the 'Carcinogenesis' page for information on the pathogenetic causes of the disease. On reflection, I think we'd need a section at least on the pathogenetic aspect (obviously headed by a 'Main article:Carciniogenesis' template). I think it would be good to find some sort of reasonable consensus on that first among our projects to prevent avoidable misunderstandings later on.

Ultimately, I think we all need to try to step back from our individual viewpoints/backgrounds in the interests of our general readership. 2c, 109.157.86.177 (talk) 21:08, 15 July 2014 (UTC)

Support trimming Pathophysiology in preference to "Causes". But is the "Pregnancy" section really necessary here? I'd be inclined to just move that to its own article, so gaining some breathing space. Wiki CRUK John (talk) 12:29, 16 July 2014 (UTC)

We often have "special population" sections. For example see obesity. Pregancy is only 4 paragraphs. It it grows could see summarizing it in one paragraph and creating a subpage. Doc James (talk · contribs · email) (if I write on your page reply on mine) 20:53, 16 July 2014 (UTC)

5 paras in fact. If it affects 1 in 1000 pregnancies it affects, what, 1 in 3000 people, and there isn't all that much really decisive to say about it. I don't think it rates 4 paras here. Childhood obesity (including overweight) affects about 28% (and rising) of children in the UK. Wiki CRUK john/Johnbod (talk) 21:40, 16 July 2014 (UTC)

IMO the use of causes to mean etiology is the more common usage of the term. If we consistently use mechanisms for pathophysiology there should not be an issue. Doc James (talk · contribs · email) (if I write on your page reply on mine) 20:57, 16 July 2014 (UTC)

How the article is divided

Cause (23.0%)
Pathophysiology (17.0%)
Management (10.0%)
Diagnosis (7.00%)
Research (5.00%)
Prevention (5.00%)
Screening (5.00%)
Signs and symptoms (4.00%)
Epidemiology (4.50%)
Society and culture (5.50%)
History (4.00%)
Definitions (1.00%)
Prognosis (3.50%)
Pregnancy (4.00%)
Other animals (0.50%)
Other (1.00%)

Here's a breakdown of what the article covers, by word count (excluding the lead). The largest wedge is ==Causes==. The second largest wedge is ==Pathophysiology==. The ==Pregnancy== section is only 4% of the article, so even blanking it completely would have little effect overall (other than making the article incomplete. Also, there should be a corresponding section for ==Children==).

If we want to have a noticeable effect on the article size, then we really have to focus on those bigger parts of the pie. It's true that I like the ==Causes== section. Since I wrote a good deal of it a few years ago, it's flattering to hear people say that they think readers will be interested in reading it. But I think it's time to split it off. WhatamIdoing (talk) 22:06, 16 July 2014 (UTC)

I could see splitting it off and summarizing what we have here more. I would go for 10 paragraphs rather than 4 though. Doc James (talk · contribs · email) (if I write on your page reply on mine) 22:40, 16 July 2014 (UTC)

There are two related but distinct questions being discussed here, which I think call for largely separate decisions:

Do we need a 'Causes of Cancer'? [Imo, definitely yes!]
How to balance this vital parent page so to make it as useful and accessible as possible to the lay general reader? [Hum, good question...]

Of course, WP:SUMMARYSTYLE is relevant to both. —109.157.86.177 (talk) 09:39, 17 July 2014 (UTC)

I've copied the content to the new page and fixed the redirect. The next little task is for someone to set importance ratings on Talk:Causes of cancer, and the next big task is to start summarizing/shortening the content of that section here. I'll take a baby step that way.

What do you all think about aiming for three subsections, roughly heredity, lifestyle, and non-lifestyle environment? WhatamIdoing (talk) 16:06, 17 July 2014 (UTC)

Other animals

Cancer and alternative medicine/CAM

Semi-protected edit request on 24 September 2014

Great graphic for incidence and mortality of different types of cancer

Here's a great chart that clearly displays the different types of cancer (lung, colorectal, breast, etc., according to number of deaths), and also gives the new cases. It does what a good chart should do -- summarizes a lot of useful information in one chart. It basically uses the principles of Edward Tufte. This is not an article on cancer, but an article on graphic design, which uses cancer mortality and incidence as an example of good design. I've seen charts like this before, but this one is open access from PLoS. I would upload it myself, but I never got around to registering for Wikimedia.

doi:10.1371/journal.pcbi.1003833 http://www.ploscompbiol.org/article/info%3Adoi%2F10.1371%2Fjournal.pcbi.1003833#pcbi.1003833-Fung1

Here's the graphic: http://www.ploscompbiol.org/article/fetchObject.action?uri=info:doi/10.1371/journal.pcbi.1003833.g001&representation=PNG_M

--Nbauman (talk) 13:00, 25 September 2014 (UTC)

Nice but US-only. I hope to get global ones from CRUK before long. Obviously, this is an area where the US is not a good proxy for the world, as developed & undeveloped world patterns vary greatly for many cancers. Wiki CRUK John (talk) 16:00, 25 September 2014 (UTC)

I don't want to be pedantic about the US/world perspective. There are 2 reasons for using US statistics:

I think the US statistics, based on the SEER database, are the most accurate statistics in the world. I read Lancet, BMJ and other UK journals, and even they use SEER statistics when they need figures for all cancers. I would expect that if CRUK had statistics, they would put them on their web site. The Europeans have statistics for individual cancers, but the SEER database collects statistics for all cancers by consistent methods with consistent definitions. I once looked into the prostate cancer statistics in detail. How do you decide when a patient has died from prostate cancer, and not one of the other comorbid conditions of aging? You can't. (Actually, SEER only collects data from the states that are in a sampling region, and they're extrapolated to the US as a whole, so they're not even US-wide statistics.) There might be Scandinavian databases that are also as accurate, but I haven't seen them.

You would lose important information if you merged data from the developed with the undeveloped world. Cervical cancer, for example has a completely different pattern in the two. In fact, I saw a Lancet international comparison, and they said that black Americans should be compared separately from white Americans, because the patters were so different.

Furthermore, I don't think there are any accurate statistics for the undeveloped world. In the Ebola epidemic now, doctors were saying that they probably only record a quarter of the cases, and that had a wide margin of error, because people often bury family members without reporting it to anybody. Any cancer statistics you could get from the undeveloped world would have wide margins of errors, and if you merge the developed and undeveloped world, you'd get combined statistics that had the same wide margin of error of the undeveloped world.

If you can find comparative statistics that are as good as the US statistics, and a plot that is as clear and informative as this one, I'd like to see it. But I don't think they exist. --Nbauman (talk) 20:51, 25 September 2014 (UTC)

Don't worry, CRUK have a sub-site on statistics, UK and global, produced by a fair-sized team of specialists - see here. Enjoy! It is precisely because the "developed & undeveloped world patterns vary greatly for many cancers" (not that you would know it from the article in its present state) that US-only statistics are inadequate. Johnbod (talk) 23:47, 25 September 2014 (UTC)

Semi-protected edit request on 3 November 2014

This edit request to Cancer has been answered. Set the |answered= parameter to no to reactivate your request.

More information Hat polemical screed ...

Hat polemical screed

The following discussion has been closed. Please do not modify it.

All cancers 3 November 2014 All cancer cells emit X rays when there exposed to low power ultrasound. This means the cell is doing molecular nuclear fusion. Turning her pressurised water into helium, oxygen, heat and X rays. There is no biochemical source of X rays! 1 H2O+US->He+O+E2+Xray In 2002 the Moffitt cancer centre applying high intensity ultrasound to prostate cancer. And got a one appointment total cure the cancer. The making medical history! I have personally validated the 150 W 40 kHz for 30 seconds is HIUS. Though I now use 5 W 1 MHz for the same time. I have even cleared late stage inoperable liver cancer. HIUS to the armpits, liver and both sides of the head will clear all secondary us. Any other secondary will be cleared by ½ minute of external HIUS. Though the immune system should clear all secondaries automatically. The biochemical drug industry went ballistic! Suddenly there is a total physical cure to cancer that does line for biochemical treatments: which provide two years of expensive and agonising life before inevitable death. ‘it just works for prostate cancer’ they argued: have no conception how it worked out all. Medics have been using ultrasound since 1826. Lower power ultrasound does 1 for all cancers. HIUS steps up the heat output! To cause the cancer cell to heat up past 120° C. At which stage in fragments! Above 60° C it is dead. All cancers have to be pressurised in order to grow in a single cell way. He also need some viral genome. So cancers are composed of fragments of viral genome left behind by a fall infections. So all cancers are cleared with HIUS! This science was medically proved by our hundred patient double blind trial in 2002. It totally removes the need for a GP or hospital involvement. Which is why all medics have agreed not to use HIUS! To totally abandoned the first repeatable total cure to all cancers. Preferring instead to do cognitive manslaughter on their own patients-for money! Since 2002 they have executed 400,000,000 people around the world. There biggest intentional mass murder of all time. The cheapest source of HIUS is an ultrasonic massage device bought over the Internet. Search for ‘5 W 1 MHz ultrasonic massage device cheapest’. When it arrives, 30 seconds of external application will clear any cancer. Both coronary heart disease, arthritis, asthma and diabetes are caused by an inflated structure left behind by infective disease. HIUS applied to the top left the chest and the kidneys will clear coronary heart disease and raised blood pressure. 1 minute of HIUS to the chest will clear asthma. To arthritic joint three of the applications will clear the arthritis: in my personal direct experience! HIUS applied to the bottom right suggest will clear diabetes. Type 1 will take three days to totally remit. Type 2 were innate within turn sections. So all the diseases Astra Zeneca has a perfect biochemical treatment for can be totally cleared using an ultrasonic massage device purchased over the Internet. The same device applied to the chest throat and nose for ½ minutes, will clear all infections. Without the need of prescription or a medic! The world change is 2002. This is 2014. Doctors have August rated the biggest deliberate mass homicide in human history. For which they have been massively paid! In total contravention of the Hippocratic oath the altar, entering Medical Service. They can no longer apply medicine! They have deletes and cells from the medical registers around the world. Too well under five medicine is massive medical malpractice. The lawyers are going to have a field day! Jonathan Thomason JonThm9@aol.com 2.99.200.218 (talk) 17:17, 3 November 2014 (UTC)

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Not done as this appears to be an unsourced rant rather than a recommendation for a specific change. Yobol (talk) 18:11, 3 November 2014 (UTC)

Semi-protected edit request on 11 November 2014

Incorrect sentence in 1st paragraph

I don't agree with first sentence of this lemma : Cancer, also known as a malignant tumor, is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. come back later with arguments and proposal for correction --DerekvG (talk) 10:39, 13 October 2014 (UTC)

Ref one says

"Cancer is a generic term for a large group of diseases that can affect any part of the body. Other terms used are malignant tumours and neoplasms. One defining feature of cancer is the rapid creation of abnormal cells that grow beyond their usual boundaries, and which can then invade adjoining parts of the body and spread to other organs."

Ref two says:

"Cancer is a term used for diseases in which abnormal cells divide without control and are able to invade other tissues. Cancer cells can spread to other parts of the body through the blood and lymph systems. Cancer is not just one disease but many diseases."

These support that cancer is also known as malignant tumor, that cancer is a group of diseases, that abnormal cell growth is involved, that their is a potential to spread or invade other body parts. Not sure what issue you see? Doc James (talk · contribs · email) (if I write on your page reply on mine) 10:56, 13 October 2014 (UTC)

One might query "a malignant tumor" at the start as encompassing all cancers, no? (oh, this is the ref, not the text: Well cancer does not = neoplasm, as the sentence rather implies/says.) Haven't we had a section on this in the last 6 months? Can't find it though. Please come back with proposal - this is absolutely the right way tio do it. Wiki CRUK John (talk) 11:18, 13 October 2014 (UTC)

Cancer does not equal neoplasm. Cancer does equal malignant neoplasm but does not equal benign neoplasm. These terms are sometimes not used correctly. Doc James (talk · contribs · email) (if I write on your page reply on mine) 11:24, 13 October 2014 (UTC)

Oh! the discussion started without me, nice, wait for me chaps let me catch up ;-)

I do agree with Doc James and with the two definitions that ref1 and ref2 provide, I think thos references actually support my statement that I don agree with the first sentence of this lemma. At least not as its worded now it implies that cancer is limited to malignant tumour and it isn't beacuse it aslo includes such cancers as lymphoma, and leukemia which to my non-medical knowledge don't have solid tumours or neoplasms, they are however "abnormnal cells with uncontrolled growth".

I woudl like to propose the following change to that sentence :

" Cancer is a generic term covering a large variety of diseases that share the following common caracterics :

- a) abnormally formed cells

- b) uncontrolled cell growth (division)

- c) with the potential to invade adjoining tissue or spread to other organs of the body.

Cancer is not limited to diseases that involve the development of malignant tumour(s), non-tumour forming diseases exist.

Not all neoplasm (solid tumour formation) is cancerous, benign tumours are excluded from the cancer group of diseases."

Thank you Wiki CRUK John for your remark that this is the way to make such fundamental changes to the wiki encyclopedia--DerekvG (talk) 11:03, 14 October 2014 (UTC)

One can have liquid neoplasms (also known as liquid tumors) (ie leukemia). And WHO uses the term neoplasm and tumor interchangeably. They do not restrict either of these words to just "solid mass". Have added malignant neoplasm as one of the possible terms.Doc James (talk · contribs · email) (if I write on your page reply on mine) 11:13, 14 October 2014 (UTC)

By the way what is a "lemma" Doc James (talk · contribs · email) (if I write on your page reply on mine) 11:13, 14 October 2014 (UTC)

A maths-derived term for a page, much used by Dutch & German speakers. Since I think we all agree that the WHO's "Other terms used are malignant tumours and neoplasms" isn't really precisely correct, and the text doesn't say that, we should look for a better ref. If we just remove "also known as a malignant tumor," aren't we all happy? Then we need something with a more qualified version of that bit, distinguishing benign/malignant & solid/not. Replacing "Not all tumors are cancerous; benign tumors do not spread to other parts of the body", how about:

"All cancers are classed as neoplasms, and most form solid tumors. Cancer is the group of neoplasms which are malignant, meaning that they spread to other parts of the body. Other neoplasms are called benign because they do not spread in this way, and so are not cancers." Wiki CRUK John (talk) 12:01, 14 October 2014 (UTC)

Indeed Wiki CRUK John, so I just outed myself as a dutch speaker, we do use the term "lemma" for a wiki subject page --DerekvG (talk) 15:54, 14 October 2014 (UTC)

Yes thanks John. The terms malignant tumours and malignant neoplasms are used and are correct because tumours and neoplasms represent both solid and liquid cancers. Doc James (talk · contribs · email) (if I write on your page reply on mine) 12:08, 14 October 2014 (UTC)

Allow me to respond to that as a patient advocate in the matter of cancer. In other discussions on Wp:MED i've defended the position that on initial pages we should make sure that anybody can read and understand clearly what is being said, that further down we get more technical and readers are supposed to "dig" further (to clarify what information they don't understand) is fairly understood and acceptable as policy. I do understand and acknowedledge the nomenclature of the WHO and different cancer research institutions and organisations such as EORTC, ACA or NCI. I think for the wikipedia reader, unfamiliar with medical terminology, we should clarify that solid tumours and liquid cancers exist and what their common caracteristics are even if we say that from that point onward the terms cancer, malginant tumour or malignant neoplasm, are considered interchangeable and covering all types of cancer (that is why I said i didn't agree with the sentence). IMHO Users of wikipedia without a medical background are most likely to drop into the subject at pages like cancer, tumor or any page with the name of a disease picked up during a converstaion with their physician, and that is why we need to provide relevant, accurate and unambiguous information or informatiopn presented in such a manner that the casual reader both understands the different aspects and nuances of the subject and that we dissipate confusion by providing the different termss that might be interchangebaly used to refer to the same thing especially if they seem to refer to a subset.--DerekvG (talk) 15:54, 14 October 2014 (UTC)

Unfortunately the whole issue(s) of solid and liquid tumors, blood cancers, fixed and mobile tumors, which I agree needs explaining, even if not all are significant medical distinctions it seems, is not clearly handled at tumor/neoplasm, liquid tumor/Tumors of the hematopoietic and lymphoid tissues, or anywhere else that I can see. We need a patch that should go in all of these in some form. Wiki CRUK John (talk) 14:01, 15 October 2014 (UTC)

Quick note: If we're trying to be absolutely accurate, then "b) uncontrolled cell growth (division)" is wrong. The "rapidly dividing cells" idea is typical of what you read in the media, but cell accumulation via immortalization (i.e., via apoptotic failure) is sufficient to earn the label cancer. WhatamIdoing (talk) 18:07, 11 November 2014 (UTC)

Isn't that still "uncontrolled"? Johnbod (talk) 02:26, 12 November 2014 (UTC)

It's not "(division)", and "accumulation" is not exactly "growth" in the way that most people think of things that are growing. If you are talking about a leafy plant, for example, "the old leaves failed to die as fast as expected" is not what people usually call "growing leaves". "Growth" in this context implies the creation of new things (leaves, cells, or whatever). WhatamIdoing (talk) 03:31, 12 November 2014 (UTC)

Confusing summary of incidence/prevalence statistics

The introduction includes the following: "In 2012 about 14.1 million new cases of cancer occurred globally.^[1] It caused about 8.2 million deaths or 14.6% of all human deaths.^[1]^[2]" ... "Skin cancer other than melanoma is not included in these statistics and if it were it would account for at least 40% of cases.^[3]^[4]"

This raises several questions. Is the fact that non-melanoma skin cancer is not included in the 14.1 million annual new cases in the WHO report stated in the WHO report itself, or is the WHO report referred to in one of the later references, the reports of the Facial plastic surgery clinics of North America? All three require a purchase or subscription to read and verify. If this statement can be verified, why is the first figure given without including non-melanoma skin cancers? And if there is a good reason, why is the exclusion not immediately pointed out? It would be clearer to say: "In 2012, about 14.1 million new cases of cancer (excluding non-melanoma skin cancers)..." The fragment of the final source that is available appears to refer to non-melanoma skin cancers as accounting for 40% of cancer cases in terms of prevalence. If that is so, it can't be directly compared to the original 14.1 million figure, as that refers to incidence. In any case, it would be clearer to show both totals (including and excluding non-melanoma skin cancers) in absolute terms, rather than setting the reader an algebra test. Cimbalom (talk) 05:04, 20 December 2014 (UTC)

Yes the statements are correct:

Per "why is the first figure given without including non-melanoma skin cancers". The reason is that non-melanoma skin cancers (basal cell and squamous cell) are not particularly serious because they are visible and easily cut of. They also very rarely metastasise.

WCR states "Results from GLOBOCAN [3] show that in 2012 there were an estimated 14.1 million new cases of cancer diagnosed worldwide (excluding non-melanoma skin cancer)"

Other ref says "Nonmelanoma skin cancer is the most common form of cancer in the world and approximately 40% of all malignancies. "

Doc James (talk · contribs · email) 05:59, 20 December 2014 (UTC)

So I've updated the paragraph to clarify from the outset that NMSC is excluded. I've also clarified that the 40% figure is a prevalence figure. I've added skin cancer into the list of the most common forms of cancer for men and women. An alternative edit without NMSC would be: "The most common types of serious cancer in males..." and likewise in females. Cimbalom (talk) 15:28, 20 December 2014 (UTC)

I doubt "the 40% figure is a prevalence figure" - cancer figures tend not to use prevalence for obvious reasons. Johnbod (talk) 16:27, 20 December 2014 (UTC)

[1]
World Cancer Report 2014. World Health Organization. 2014. pp. Chapter 1.1. ISBN 9283204298.
[2]
"The top 10 causes of death Fact sheet N°310". WHO. May 2014. Retrieved 10 June 2014.
[3]
Dubas, LE; Ingraffea, A (Feb 2013). "Nonmelanoma skin cancer". Facial plastic surgery clinics of North America. 21 (1): 43–53. doi:10.1016/j.fsc.2012.10.003. PMID 23369588.
[4]
Cakir, BÖ; Adamson, P; Cingi, C (Nov 2012). "Epidemiology and economic burden of nonmelanoma skin cancer". Facial plastic surgery clinics of North America. 20 (4): 419–22. doi:10.1016/j.fsc.2012.07.004. PMID 23084294.

Adjusted a little further. Yes it is incidence not prevalence. We already mention that these states do not contain non melanoma skin cancers and this applies to all three of the first sentences. Doc James (talk · contribs · email) 19:45, 20 December 2014 (UTC)

Semi-protected edit request on 29 December 2014

On a related matter...

One of the opening sentences of ==Causes== currently reads :

Common environmental factors that contribute to cancer death include tobacco (25–30%), diet and obesity (30–35%), infections (15–20%), radiation (both ionizing and non-ionizing, up to 10%), stress, lack of physical activity, and environmental pollutants.⁴

I've requested clarification on the Causes of cancer page^{(the present page is semi-protected)} as to how "obesity" can be listed/counted as "environmental" – when it isn't, given that it's not an external factor. A somewhat similar consideration could be made for "stress" (ie the organism's response, as distinct from environmental stressors).

This 'review' source (PMID 18626751) from 2008 is actually *proposing* a "unifying hypothesis". I feel PMID 24351322^paywalled and PMID 23514316^paywalled might be useful recent MEDRS.

@HenryScow: Perhaps WikiProject CRUK could somehow help get this key cancer-related content right? 86.134.203.235 (talk) 17:07, 22 January 2015 (UTC)

If we're doing it here, I'll repeat here the comment I made on that talk page:

I'm not happy about this edit , which leaves the start of the article not making much sense. The previous version, I think adjusted by me following a discussion elsewhere (in which 86 participated as 109), defined "environmental", as used by epidemiologists, as anything not caused by inherited genetics, so including obesity, as well as sporadic "bad luck" cancers. This was supported by the 1st ref (although it comes after that ref, which is of course too old (2008) and I think rather tendentious in implying that all such cancers are preventable), whose use of "environmental" explicitly covers obesity. Now the sum using that definition (90-95 + 5-10 = 100) remains right at the start ("The great majority of cancers, some 90–95% of cases, are due to environmental factors. The remaining 5–10% are due to inherited genetics"), but the definition of "environmental" has been significantly altered, leaving no place in that implied sum for "internal" environmental factors, and "bad luck" ones, which actually represent the majority of cases! We could do with better sources, of course, but either the whole para should be changed, or left.

User:WhatamIdoing, what do you think? Wiki CRUK John (talk) 12:46, 22 January 2015 (UTC)

- It all goes back to an earlier discussion on this page, now archived (link in quote). The "ref 1" at causes is this, which is very happy to describe both obesity and sporadic "bad luck" as "environmental factors". Wiki CRUK John (talk) 17:30, 22 January 2015 (UTC)

I think it "all goes back" to whether we're actually getting it right or not... Restarting with more appropriate sources might help, imo. I agree that environmental factors + inherited genetic factors = 100% (in terms of factors that are *preventable* – in the broadest possible sense). Other individual factors such as obesity and stress are 'downstream' of that equation. Btw, in the present (ie epidemiological) context there's no such thing as "internal" environmental factors. 86.134.203.235 (talk) 18:04, 22 January 2015 (UTC)

I think that the problematic edit is this one, which uses a completely different (and minority) definition and then claims that it applies to the stats produced using the original definition. That is not exactly an example of "getting it right".

To give you an idea of how significant this difference is, the definition that was added declares that the number of children a woman has, the age she starts having children, and whether and how long she breastfeeds—which are all significant biological factors in sporadic breast cancer due to "inside the body" hormones—are entirely non-environmental. Back here in the real world, those are seriously cultural factors, and human culture is definitely environmental. Worse, since this paragraph sets up a binary system, it effectively implied that these are therefore somehow hereditary genetic factors, which is just nonsense. (Obesity, by the way, is the cancerous tissue's environment, so that's not even as wrong as it sounds when you first hear it.)

I've reverted for now. I think we need improvements, but this attempt wasn't working. My general recommendation is that when we're presenting definitions and statistics, then we need to have the definition match the one used by the people producing the statistics. Perhaps the first place to start is with a proper lead sentence, like "There are many causes of cancer. Most of them cannot be easily controlled by individuals." It might also help to put the "hereditary genetics" first, so that the category of "non-hereditary genetics" seems more natural. WhatamIdoing (talk) 18:18, 22 January 2015 (UTC)

WAID, could you perhaps look at that again? In particular, on what basis do you say the definition I paraphrased is "completely different" (and minority)"? It's supported by highly authoritative sources,^[1]^[2] as well as the "original" source^[3] (which was/is being misrepresented here]). No-one is disputing that obesity is *related* to environmental factors – just that it's NOT itself an environmental factor.

[1]
A Dictionary of Epidemiology. Oxford University Press. 2014. p. 93. ISBN 978-0-19-997673-7. ENVIRONMENT: All that which is external to the individual human host
[2]
Cancer and the Environment: What you Need to Know, What You Can Do. NIH Publication No. 03-2039: National Institutes of Health. 2003. Cancer develops over several years and has many causes. Several factors both inside and outside the body contribute to the development of cancer. In this context, scientists refer to everything outside the body that interacts with humans as 'environmental'.{{cite book}}: CS1 maint: location (link)
[3]
Kravchenko J, Akushevich I, Manton, KG (2009). Cancer mortality and morbidity patterns from the U. S. population: an interdisciplinary approach. Berlin: Springer. ISBN 0-387-78192-7. The term environment refers not only to air, water, and soil but also to substances and conditions at home and at the workplace, including diet, smoking, alcohol, drugs, exposure to chemicals, sunlight, ionizing radiation, electromagnetic fields, infectious agents, etc. Lifestyle, economic and behavioral factors are all aspects of our environment.{{cite book}}: CS1 maint: multiple names: authors list (link)

86.134.203.235 (talk) 18:44, 22 January 2015 (UTC)

Adding: I've been trying to understand WAID's objection above (stemming from a simple misreading of this version maybe?). Perhaps it regards the choice of the NIH source (ref 2, above), with its rather specific focus on environmental "substances"? Having some professional background in epidemiological / environmental health research myself, I didn't (and don't) see that brief definition as conflicting in any real way with the more extensive definition provided by Kravchenko et al in ref 3. However, I'm not wedded to use of any one particular source. Fwiw, I do agree that further elucidation is needed (which is why I pinged User:HenryScow at CRUK, who clearly has a good overall grasp of these causality questions). 86.134.203.235 (talk) 23:03, 22 January 2015 (UTC)

If we are saying that "environmental factors" is restricted to those arising outside the body then the opening sentence "The great majority of cancers, some 90–95% of cases, are due to environmental factors" just isn't true, surely? Wiki CRUK John (talk) 23:39, 22 January 2015 (UTC)

That is exactly the problem. WhatamIdoing (talk) 23:45, 22 January 2015 (UTC)

Sorry, I hadn't seen you've addressed that in the article. Wiki CRUK John (talk) 23:48, 22 January 2015 (UTC)

(ec) adding: Talking of the US, one of the PMID links above, "Current perspective on the global and United States cancer burden attributable to lifestyle and environmental risk factors", by Schottenfeld D1, Beebe-Dimmer JL, Buffler PA, Omenn GS, gives (in the abstract) a maximum of 60% of US cancers to the big external environmental factors plus infections. The big UK survey of a year or two back gave around 45% to the big external environmental factors as I recall. You only get to 90-95% by adding sporadic unexplained mutations, as the first ref used does. Wiki CRUK John (talk) 23:46, 22 January 2015 (UTC)

86.134, perhaps it will be easier if you try to explain what pregnancy-related hormones are. Are they "outside the body", or not? Well, no, obviously hormones are inside the body. And if they're not "outside the body", then are they "inherited genetics"? Well, no, the are obviously not inherited genetics. So what are they?

This paragraph is using a strict binary system: All causes of cancer, without exception, are either A or not-A. All causes of cancer, without exception, are either in the group that causes 90–95% of cancers, or in the group that causes 5–10% of cancers. This simple pie graph shows the central point that we're talking about. There are only two pieces in the pie. All causes are either one or the other. One piece is labeled "Genes" and the other is labeled "Environment". We want to tell people what those two numbers are. We want them to know that one of those numbers involves way the heck more than pollution.

You have just (accidentally) re-defined one of the terms so that we now have logical nonsense. You have re-defined it so that we have 90–95% caused by "things outside the body", 5–10% caused by "inherited genetics", and 0% leftover for the very sizable contribution of things inside the body that are not inherited genetics (for example, pregnancy-related hormones).

You seem to want to create a trinary system:

things outside the body that cause cancer (e.g., pollution),
things inside the body that are not hereditary genetics and cause cancer (hormones), and
inherited genetics

—but if we do that, then we need a different statistics (i.e., statistics that nobody has been able to find, because good sources don't make that particular three-way distinction).

If we could find stats, we could use the other binary system:

Internal factors (both inherited genes and hormones)
External factors (both pollution and sunlight)

but I haven't seen recent reliable sources with statistics for this system.

As I see it, the immediate realistic options are either:

Remove the definition that is not used by the people who created these statistics, or
Remove the statistics that are not following the definition posted on the unrelated website you cited.

What we cannot do is say that "A" is defined this way, and then say that "A" is 95%, when we know perfectly well that the people who said "95%" used a noticeably different definition for "A". It would be like saying that "Luxury cars are defined by source #1 as any automobile with air conditioning" and then saying that luxury cars cost an average of US $90,000—according to source #2, whose definition of "luxury cars" had very little to do with the presence of air conditioning. That's what we've got right now, and it needs to be fixed right now. The definition and the stats need to be congruent. That means telling the reader that this 95% "environment" group includes far more than "substances outside the body". WhatamIdoing (talk) 23:49, 22 January 2015 (UTC)

@WhatamIdoing: This conversation seems to me to be going off-track. Fwiw, as I indicated in my comment above, in the field of environmental epidemiology, individual factors like obesity, stress, pregnancy-related hormones are understood as being *related* to environmental factors (such as diet, physical activity, sleep etc; stressors; and the ones you yourself mention above), but they aren't considered, in themselves, to be environmental factors. Since (with genuine respect) I don't think it's altogether reasonable to require a Wikipedia editor to expound in any depth on the methodological relevance and implications of such matters, instead I'll try to reframe my genuine editorial concerns here in purely WP terms.

(Btw, what you call a "simple pie graph" I do not look upon in any way as being a *simple* pie chart – though as far as I can see the information (confusingly) presented in it appears to be unsourced and, presumably, represents original research work conducted by the authors themselves, using unspecified methods.) 86.134.203.235 (talk) 10:13, 23 January 2015 (UTC)

That's a deep link to a diagram in a review article. If you want to read the methods, then you need to read the rest of the paper.

(I wonder why "diet, physical activity, sleep etc" are not considered "individual factors". Surely they are not group factors, and the mechanism for sleep, at least, ought to be in the same general class as the mechanism for obesity.) WhatamIdoing (talk) 15:56, 23 January 2015 (UTC)

@WhatamIdoing: RE If you want to read the methods, then you need to read the rest of the paper. Erm, what "methods", where? The only explanation of methods that I've been able to find is in the caption to the figure. In particular: A provides no indication of how or where the 5–10% / 90–95% ratio was obtained (and the relevant paragraph at the start of the 'Prevention of cancer' section of the main text is completely unsourced); although B at least provides a bit more information about what the figures are intended to represent, it also says "data shown here is taken from a study conducted in Utah..." (hmm... what study on what population, using what methods? have those data even been peer-reviewed?); C again gives some information on what the figures represent ("the attributable-fraction of cancer deaths due to the specified environmental risk factor") but doesn't explain how those estimates were extracted, or how the authors avoided pitfalls such as counting the same data twice in different categories. That's not what I would call an acceptable description of methods.

But, like I said, my understanding of MEDRS is that a Wikipedia editor shouldn't be expected to provide a detailed critical appraisal ("review") of a paper's methodology to question the editorial weight given in Wikipedia to the data it reports. Anyway, per WP:MEDASSESS, I've seriously questioned (I think) "the quality of the study". I've also pointed out that the content of the paper was "outside the journal's normal scope" (not altogether surprisingly, imo).

Disclaimer: I have absolutely no POV to push – I just don't think we should be giving such a strong encyclopedic voice to these figures. I believe it's unjustified and, ultimately, mistaken and unhelpful. Rather, we should also be considering how other potential MEDRS^{[including "ideal" ones]} approach these matters (see below). 86.134.203.235 (talk) 17:55, 23 January 2015 (UTC)

Arbitrary break: some MEDRS considerations

Although the paper in question is presented and indexed as a review, it claims (at the start of the Conclusions) to "propose a unifying hypothesis". On purely WP editorial grounds, I think we're conferring undue weight to one particular possible MEDRS (one which also happens no longer to satisfy WP:MEDDATE). WP:MEDRS specifically warns about using articles whose "content [is] outside the journal's normal scope", as is the case I think of this environmental epidemiology paper published in an off-topic journal called Pharmaceutical Research

I've already proposed two alternative potential MEDRS (both unfortunately paywalled), which I think could be considered here: PMID 24351322 and PMID 23514316.^[1]^[2]

86.134.203.235 (talk) 10:13, 23 January 2015 (UTC)

The 'Etiology' section in the WHO 2014 World Cancer Report begins:
Most cancers are associated with risks from environmental, lifestyle, or behavioural exposures.
I think this could be a reasonable starting point (something like this perhaps?). As far as I can see, the report doesn't attempt to provide any more specific estimates regarding proportions of cases of this heterogeneous class of diseases that can be attributed to these overlapping categories of exposure (something I don't find altogether surprising). 86.134.203.235 (talk) 11:02, 23 January 2015 (UTC)
To avoid this problem, I have previously proposed describing these two categories as "genetic and non-genetic", but that disturbs people who say that all cancer is genetic (which is not unreasonable). (That's when we fell back to the approach of telling readers that the source was using specialist jargon.) WhatamIdoing (talk) 15:56, 23 January 2015 (UTC)

I only have a short break, away from any desk, but there is a large recent UK study, referred to above. In Nature or the BMJ I think. I tried to reference that somewhere a while back, but it was removed by Doc James as primary which slightly puzzled me at the time. The WCR is indeed remarkably unforthcoming about the overall picture, and their factsheet, used as a ref later in the lead, is a far from ideal source, with a string of large % figures, which we use, shortly followed by saying (something like) "30% of cancers are preventable", which we don't use. In general we should identify 1 or 2 big detailed sources & follow them consistently. I'm back in the office on Monday & will try to consult. Wiki CRUK John (talk) 16:29, 23 January 2015 (UTC)

@Wiki CRUK John: Was that large recent UK study perhaps PMID 22158327 (added here). If so , yes, that is indeed technically a primary source, per the MEDRS definition. Personally, as I hinted above, I'm not the surprised that the WCR avoids getting caught up in this methodological conundrum, and on both scientific and editorial grounds I can't help wondering whether we shouldn't be avoiding it too. But I suppose that isn't really the usual WP way... (as in... why waste a chance to bash out a good controversy?) Imo, an impartial MEDRS-based editorial indication might come from perusing the content of PMID 24351322 and PMID 23514316 (already suggested above), alongside the reticent WCR summary, and any other potentially appropriate, recent secondary sources. 2c / 2p (or whatever...), 86.134.203.235 (talk) 19:17, 23 January 2015 (UTC)

Yes, thanks, that's the one. I know what you mean, but it surely is not unreasonable for the reader to expect some quantification, however caveated and vague, on these points - meaning both readers of our Causes article and the 600 page-long WCR. If the IARC don't feel confident to attempt an overall synthesis of the data in that (& I too have looked, & failed to find this), then they should not put out very short fact sheets that do, with obvious problems & Wikipedia-like internal contradictions. At least we say where our numbers came from, allowing debates like this one. My opinion anyway. Wiki CRUK John (talk) 15:41, 25 January 2015 (UTC)

Agree. Let's take a look, shall we? (@Wiki CRUK John: could you help me access PMID 24351322 and PMID 23514316? tks) 86.134.203.235 (talk) 20:12, 25 January 2015 (UTC)

This review^{[when published?]} also seems pertinent.

From a ^wp:weight perspective, I feel we need to bear in mind that these estimates generally reflect *all* cancer deaths, lumped together, without distinguishing in any way between people with a good life-expectancy cut down in the prime of their life by fulminating diseases and, say, very elderly people with significant comorbidities that were already affecting their quality of life. So, on encyclopedic grounds, I feel we would do well not to overemphasize the question, especially given the limited amount of reliable information that is available on this topic, which (apart from theoretical considerations regarding prevention) also has subtle human implications. 2c, 86.134.203.235 (talk) 09:53, 26 January 2015 (UTC)

I'm puzzled why you think the Guardian editorial supports what you are arguing! Wiki CRUK John (talk) 12:14, 26 January 2015 (UTC)

Oh... then, perhaps I hadn't noticed *what* I was actually *arguing*[!^?] One of the things I was trying to point out was that the way Wikipedia presents this question may not be humanly trivial for our readers. I think the Guardian editorial (disclaimer: which represents the newspaper's opinion, not mine) illustrates that concept. 86.134.203.235 (talk) 12:51, 26 January 2015 (UTC)

Arbitrary break: pertinent MEDRS

Here are the pertinent passages, I think, from the main text of the two paywalled MEDRS suggested above.

From the Lancet 2014 review:^[1]

Primary prevention
An overall estimate of preventable cancers
Genetic variants are unlikely to account for a major proportion of cancer cases; 5–10% are attributable to highly penetrant mutations such as in BRCA1 or mismatch repair genes, and an unknown proportion to the interaction between low-penetrant variants and external risk factors. For a long time, since the publication of Doll and Peto’s The causes of cancer^{83: PMID 7017215 (1981)} containing estimates for the USA, the proportion of cancers in a population that is attributable to known risk factors has been a controversial issue. The most recent estimates have been provided by Parkin and colleagues^{85 (the big primary study suggested above by John - PMID 22158327)} for the UK. Parkin and colleagues’ report⁸⁵ has several merits: past exposures are considered in relation to present cancers (to take latency into account); risks are estimated with attainable levels of exposure as reference categories; and 14 risk factors and 18 cancer sites are considered. The conclusion is that 45% of cancers in men and 40% in women could have been prevented had risk factors been reduced to the optimum levels or eliminated (eg, tobacco).
Estimates of the proportion of cancers that can be prevented will differ substantially geographically, showing the prevalence of different risk factors, hence the need to set prevention priorities at a local and regional level.¹ This need is best characterised within the categories of the low-HDI and medium-HDI countries, where the estimates from the USA and the UK cannot be directly applied. In simpliﬁcation of messages for political effect, it is important to avoid a failure to adapt and support solutions that will bring the most beneﬁts for public health to particular settings.

From the 2013 paper by Schottenfeld et al:^[2]

ALLEVIATING THE BURDEN OF CANCER IN THE UNITED STATES AND OTHER WESTERN COUNTRIES
In their 1981 publication, Doll & Peto concluded that 75–80% of cancer deaths in the United States could have been avoided. The overall estimates reﬂected uncertainties about “diet” (PAF = 35%, range: 10–70%), but without estimating attributable fractions for obe- sity or physical inactivity, and uncertainty about attributable risks for various infectious agents (27). Doll & Peto deﬁned “diet” as “all materials that occur in natural foods, are produced during processes of storage, cooking, and digestion, or added as preservatives, or giving foods color, ﬂavor or consistency” (p. 1226). Our current perspective for industrialized countries is summarized for the United Kingdom, France, and the United States (Table 3). The data show contrasting estimates for the three countries. In the review by Parkin, 14 lifestyle and environ- mental risk factors were responsible for 43% of cancer cases (45% in men, 40% in women) and for ∼50% of cancer deaths in 2010. In addition to the risk factors reviewed in detail above, Parkin assessed four dietary factors— low consumption of fruits and vegetables [PAF (combined men and women) = 4.7%], red and processed meat consumption, low dietary ﬁber, and salt—and oral contraceptives, hormone replacement therapy, and reproductive factors. In their review of biologic agents, lifestyle behavioral patterns, and physical environmental factors that are established determinants of cancer incidence and mortality, Colditz & Wei (20) concluded that 50–60% of cancer deaths and more than 60% of cancer cases in the United States were potentially avoidable. Similarly in our analysis we suggest that 60% of cancer deaths in the United States may be attributable to eight risk factors. Because we may assume some degree of overlap in the distribution of such combinations of risk factors as tobacco and alcohol, and obesity and physical inactivity, our estimate of 60% may represent a maximal upper limit. The contrast between France and the United States is apparent for obesity and may be explained by the lower estimate for the prevalence of obesity of ∼7% in French women (PAF: all cancers = 3.3%) and of ∼6% in men (PAF: all cancers = 1.4%) (99).
...
SUMMARY POINTS
...
3. The epidemiology and pathogenesis of eight lifestyle risk factors are estimated to be determinants of ∼60% of cancer mortality in the United States. These risk factors include tobacco, alcohol, ionizing and solar radiations, occupations, biologic agents, obesity, and physical inactivity.

Thoughts? 86.134.203.235 (talk) 11:11, 28 January 2015 (UTC)

I've now read both of these (skipping some risk sections in Schottenfeld), and they are both highly useful refs, for many articles (including the uncreated Obesity and cancer). Thanks for finding them. Among other things the detailed coverage of Parkin et al.'s UK study, in the passage quoted above and elsewhere, allows this stuff to pass MEDRS. I think we should replace nearly all the existing lead and sources on these points in the "Causes" article with a rewrite using "preventable" rather than environmental, with explanations, then inherited genetics, then mentioning the existence of a remainder (these two are not so helpful here, & new sources might be needed). The Schottenfeld also has a very nice bit on the overall mechanism for causes. Note that here at Cancer the start of the causes lead is repeated. Wiki CRUK John (talk) 13:13, 28 January 2015 (UTC)

Both Wikipedia articles rely heavily for causes/risks on: Anand P, Kunnumakkara AB, Kunnumakara AB, Sundaram C, Harikumar KB, Tharakan ST, Lai OS, Sung B, Aggarwal BB (September 2008). "Cancer is a preventable disease that requires major lifestyle changes". Pharm. Res. 25 (9): 2097–116. doi:10.1007/s11095-008-9661-9. PMC 2515569. PMID 18626751. - from 2008, which now should be replaced. Wiki CRUK John (talk) 14:47, 28 January 2015 (UTC)

Agree. Is this silent consensus? 86.174.50.88 (talk) 10:11, 4 February 2015 (UTC), ex-86.134.203.235, etc

[1]
Vineis P, Wild CP (2014). "Global cancer patterns: causes and prevention". Lancet. 383 (9916): 549–57. doi:10.1016/S0140-6736(13)62224-2. PMID 24351322.
[2]
Schottenfeld D, Beebe-Dimmer JL, Buffler PA, Omenn GS (2013). "Current perspective on the global and United States cancer burden attributable to lifestyle and environmental risk factors". Annu Rev Public Health. 34: 97–117. doi:10.1146/annurev-publhealth-031912-114350. PMID 23514316.

Recent study large role for 'bad luck'

The introductory paragraph suggests that Cancer can be prevented by a healthy lifestyle, which is incorrect. It should state something that the chance of developing cancer is influenced by lifestyle. However a recent study^[1] showed that the number of stem cell divisions can explain why certain organ tissues are more likely to give rise to cancer, i.e. the more often the stem cells divide, the higher the chance of a mutation that leads to cancer can occur. This study claimed that 65% of cancer cases can be explained by bad luck. Just to clarify, this has nothing to do with genetic predisposition to develop certain types of cancer. Suggestions on how to implement this in the introductory paragraph? — Preceding unsigned comment added by 128.176.213.7 (talk) 17:35, 6 January 2015 (UTC)

References

[1]
Science 2 January 2015: Vol. 347 no. 6217 pp. 78-81 DOI: 10.1126/science.1260825

I heard that story too and I'd love to see it mentioned somehow. Problem is it doesn't quite meet WP:MEDRS since its primary research. BakerStMD T|C 20:34, 17 January 2015 (UTC)

The paper is not primary research, since it is a correlation study based on collected patient data in the entire US and estimated 'division rates' in various tissues obtained from literature — Preceding unsigned comment added by 2A02:908:FD51:AA60:E9AC:4A93:6E0A:695E (talk) 01:34, 5 February 2015 (UTC)

I can see nothing in the lead that "suggests that Cancer can be prevented by a healthy lifestyle", which is indeed incorrect. Johnbod (talk) 20:37, 17 January 2015 (UTC)

Please note that disease prevention does not only mean *eliminating* (eradicating) risk of disease, but also significantly *reducing* the risk. A healthy lifestyle does not mean that you won't get cancer, but that you'll be less likely to get it. 86.134.203.235 (talk) 18:55, 21 January 2015 (UTC)

Need a secondary source. This is primary Doc James (talk · contribs · email) 00:30, 18 January 2015 (UTC)

That study is limited by presenting data for only most cancers, but not for two of the most common (breast and prostate). "65% of some cancers" is not as interesting as "65% of all cancers".

Johnbod, a great deal of the lead talks about lifestyle, without coming right out and saying "lifestyle causes almost all cancers". See "Many cancers can be prevented by [long list of healthful lifestyle choices]". The lead completely omits the fact that most invasive cancers in non-smokers, i.e., more than 50% of cancer cases, cannot be prevented through individual action ("lifestyle choices"), and that many cannot be prevented through collective action (like curbing polluting industries), either.

However, there is significant overlap here. How does drinking scalding hot tea cause esophageal cancer? Because it increases the rate of cell division. How does alcohol abuse cause liver cancer? Because it increases the rate of cell division. Do we attribute those cases to "bad luck" or to "lifestyle choices"? It's kind of both. "Bad luck" explains why some people who engage in the risky behavior get cancer, and "good luck" explains why some people who engage in the risky behavior do not.

Looking over the list, some of the other items may or may not be in the list of "lifestyle choices": The main sources of infectious caner are sexually transmitted infections. Neither this article nor the main article on infectious causes of cancer even mention how the typical person acquires these infections. Having a lot of sexual partners is usually an individual lifestyle choice (we all hope, right?), but whether to get multiple expensive vaccines isn't always a choice, and even lifelong monogamy is not a guarantee. I also wonder if "getting vaccinated" is the right way to present the infectious disease component in the lead. It is a rather Western-wealthy-country-centric approach, and there aren't vaccines for all of the infectious agents. "Avoid getting certain sexually transmitted viruses" (regardless of the means you employ to avoid getting infected) is more accurate. I expect that the Wikipedia community would be a bit squeamish about non-drug approaches to STI control, though. WhatamIdoing (talk) 18:09, 18 January 2015 (UTC)

It doesn't say anything at all like "lifestyle causes almost all cancers"! The main bit, before what you quote, is "Tobacco use is the cause of about 22% of cancer deaths.[1] Another 10% is due to obesity, a poor diet, lack of physical activity, and drinking alcohol.[1] Other factors include certain infections, exposure to ionizing radiation, and environmental pollutants.[4] In the developing world nearly 20% of cancers are due to infections such as hepatitis B, hepatitis C, and human papillomavirus.[1]", then 10% for inherited genetics. So the main individual "lifestyle" factors account for 32%, which clearly isn't even "most", never mind "almost all". Adjust the wording if you like - the headline from the paper was nothing new & that most cancers are sporadic can be referenced easily enough. Wiki CRUK John (talk) 18:41, 18 January 2015 (UTC)

John, don't do the arithmetic. Most of our readers won't. Instead, count up the number of things that are (or could be) counted as "choices" that cause cancer, and compare it to the amount of space given to things completely outside the patient's control. I'll save you some trouble. Here's the relevant parts of the lead text. I've color-coded it.

Tobacco use is the cause of about 22% of cancer deaths.[1] Another 10% is due to obesity, a poor diet, lack of physical activity, and drinking alcohol.[1] Other factors include certain infections, exposure to ionizing radiation, and environmental pollutants.[4] In the developing world nearly 20% of cancers are due to infections such as hepatitis B, hepatitis C, and human papillomavirus.[1] These factors act, at least partly, by changing the genes of a cell.[5] Typically many such genetic changes are required before cancer develops.[5] Approximately 5–10% of cancers are due to genetic defects inherited from a person's parents.[6]

Many cancers can be prevented by not smoking, maintaining a healthy weight, not drinking too much alcohol, eating plenty of vegetables, fruits and whole grains, being vaccinated against certain infectious diseases, not eating too much red meat, and avoiding too much exposure to sunlight.[8][9]

I've highlighted "all your fault" in orange, things that the typical person might believe could go either way in yellow (people might disagree, for example, on whether working as a radiology tech or living in a smoggy city is a "lifestyle choice"), and things that are "not your fault" in green. Here are the questions you need to answer:

Does that seem about right to you? Thinking about the perception of the median patient, with median education attainment (in the US, that's a high school diploma), would you put anything that I've marked as orange into the green category?
Which color do you see the most of? WhatamIdoing (talk) 04:25, 19 January 2015 (UTC)

Of course. But what do you do? You can add more green, but that doesn't take long at this level of simplicity. Then do you cut the orange and yellow to reflect a "correct" balance? At the end of the day the orange is relatively complex information that you can do something about and the green isn't either of those, which is why it tends to get predominance in coverage. The 3rd world infectious causes count as "not your fault"/nothing to worry about for Western readers surely? Wiki CRUK John (talk) 09:03, 19 January 2015 (UTC)

Worth remembering perhaps that lifestyle choices ≠ individual fault (culture is a key player). 86.134.203.235 (talk) 19:48, 21 January 2015 (UTC)

86.134, you're not an American, are you?

John, I don't think that it can be usefully solved. It simply takes more words to write a basic explanation for the "what you can do" part than for the "you're helpless about the rest" part. But the result is that readers will feel like cancer is mostly under individual control. We could maybe add another sentence that says something like, "Most cancers cannot be prevented solely through individual lifestyle choices", and perhaps put that first instead of last, but I don't think that the problem can be easily solved. WhatamIdoing (talk) 18:03, 22 January 2015 (UTC)

I agree (about the last point). Wiki CRUK John/ Johnbod (talk) 03:14, 24 January 2015 (UTC)

Here, btw are User:HenryScow's thoughts on the original study and it's press coverage. Wiki CRUK John (talk) 14:52, 20 January 2015 (UTC)

That's a healthy read :) 86.134.203.235 (talk) 20:00, 21 January 2015 (UTC)

Inducing cancer through transplant:Cornelius Rhoads

In Principles of Research Methodology: A Guide for Clinical Investigators, on page 235, it mentions that Dr. Cornelius Rhoads was able to successfully transplant cancer cells that resulted in the deaths of 8 patients. Most people do not think cancer is something that can be spread through transplant, this information is worth mentioning in this article as it applies to all cancers. Bullets and Bracelets (talk) 15:19, 22 March 2015 (UTC)

Wow. The guy was an asshole, evidently, but it seems that "successfully transplant" is not true, based on the information in the article on him. In the quoted part of his letter (Cornelius P. Rhoads § Scandal), he claims "credit" for killing 8 patients (presumably by other malpractice than cancer transplant), but he indicates that his attempts to transplant cancer were not successful so far; and in the 2002-2003 section (Cornelius P. Rhoads § Revival of controversy), it says that no one could find evidence that the cancer transplants worked, but that the guy was a dick for sure. Quercus solaris (talk) 17:10, 22 March 2015 (UTC)

It happens in Tasmanian devils with concerns it may lead to there extinction. Doc James (talk · contribs · email) 23:57, 22 March 2015 (UTC)

Wow again. I never knew that clonally transmissible cancer existed, but I just looked over the WP article. Thanks for the tip. Quercus solaris (talk) 02:04, 23 March 2015 (UTC)

Did Dr. Rhoads experiment doing the cancer transplant with different transplant rejection drugs; did he, (or anyone else since than), try cordyceps? Has their been research on cancer transplants? Bullets and Bracelets (talk) 17:23, 23 March 2015 (UTC)

There's more on this subject from Scientific American. It appears there are cases in medical literature where cancer has been transmitted from a patient onto a surgeons cut, and between two genetically similar people. Also, a mother can pass cancer on to a fetus—for example, things like melanoma have been passed from mother to fetus, and during organ transplantation, if the organ donor has cancer, it is possible to transmit cancer. Bullets and Bracelets (talk) 03:12, 28 March 2015 (UTC)

I think we have enough on this here, given how rare it is, but the other articles might be added to - Clonally transmissible cancer etc. Johnbod (talk) 14:00, 28 March 2015 (UTC)

Addition

Reference 5 is not the cause of reference 1

Gen manipulation

Semi-protected edit request on 7 July 2015. Added to Causes->chemicals section

External links modified

Causes, MEDRS?

The great majority of cancers, some 90–95% of cases, are due to environmental factors. The remaining 5–10% are due to inherited genetics.[5] Common environmental factors that contribute to cancer death include tobacco (25–30%), diet and obesity (30–35%), infections (15–20%), radiation (both ionizing and non-ionizing, up to 10%), stress, lack of physical activity, and environmental pollutants. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2515569/)

Is that source a WP:MEDRS? It claims that power lines and mobiles cause cancer, list a load of herbs en chemicals with supposed "anticancer activity", and as conclusion it proposes a unifying hypothesis about how everything is linked to chronic inflammation, the nuclear transcription factor NF-κB.

Low-frequency electromagnetic fields can cause clastogenic DNA damage. .. For instance, children living within 200 m of high-voltage power lines have a relative risk of leukemia of 69%, whereas those living between 200 and 600 m from these power lines have a relative risk of 23%. In addition, a recent meta-analysis of all available epidemiologic data showed that daily prolonged use of mobile phones for 10 years or more showed a consistent pattern of an increased risk of brain tumors

On the basis of the studies described above, we propose a unifying hypothesis that all lifestyle factors that cause cancer (carcinogenic agents) and all agents that prevent cancer (chemopreventive agents) are linked through chronic inflammation (Fig. 10). The fact that chronic inflammation is closely linked to the tumorigenic pathway is evident from numerous lines of evidence. Ssscienccce (talk) 04:02, 12 September 2015 (UTC)

It's also from 2008 in what I think is an obscure non-specialist journal. I think a probably more significant, and certainly more recent, UK study was rejected as primary last year. Yes - Talk:Cancer/Archive_6#Causes_of_cancer (July 2014) Talk:Cancer/Archive_6#On_a_related_matter... (Jan 2015). We could certainly do with a better source, and an explanation of "environmental" here, which will mislead almost all of the general public. Johnbod (talk) 12:55, 12 September 2015 (UTC)

Hallmarks of cancer

WHO on processed & red meat

To the editors:

External links modified

Deaths due to Cancer

Semi-protected edit request on 14 May 2016

Semi-protected edit request on 13 June 2016

Cancer Patients and Depression

Hello everyone, I'm interested in adding to this page because I believe mental health is often overlooked amongst cancer patients. Most individuals are unaware that diagnosis of cancer comes with a greatly increased likelihood of diagnosis of depression. As a large source of information, adding to this Wikipedia page can help inform/warn people of its seriousness and prevalence, which can help aid in awareness and diagnosis.

With diagnosis of cancer comes an increased likelihood of diagnosis of depression. Amongst cancer patients, 58% show depressive symptoms and 38% of patients fully develop Major Depressive Disorder (MDD). While depression can be detrimental to everyday life, it also greatly impacts quality of life, or someone’s perspective of their role within their environment and their position among their immediate and long-term desires, goals and needs. Quality of life is essential to consider amongst cancer patients because a mental state-of-mind could ultimately effect a patient’s physical well-being and survival. Some studies suggest that those with higher quality of life perspectives tend to survive longer than those with lower ones.Depression and mental health of patients is an important aspect of cancer patient treatment and survival. ^[1]^[2]^[3] Diagnosing depression amongst cancer patients is a difficult task. Symptoms of MDD, such as appetite loss, disturbed sleep and decreased energy, naturally overlap with the disease’s symptoms and treatment. It may be more efficient to have two separate diagnosis processes for cancer patetients versus healthy patients. Experts suggest that self-assessments could be more appropriate, also for busier departments with less trained personnel. Additionally, another challenge is that hospital staff don’t often see the prevalence of depression because cancer patients don’t often open up to non-psychiatric personnel. The great variation in disease phase, stage of treatment and social and cultural variation is another obstacle in creating an accurate and efficient diagnosis. More research and studies need to be done on the overall prevalence and effect of depression amongst cancer patients. ^[4]

[1]
National Institutes of Health State-of-the-Science Conference Statement: Symptom Management in Cancer: Pain, Depression, and Fatigue, July 15-17, 2002. (2003). JNCI Journal of the National Cancer Institute, 95(15), 1110-1117. doi:10.1093/jnci/djg014
[2]
The World Health Organization quality of life assessment (WHOQOL): Position paper from the World Health Organization. (1995). Social Science & Medicine, 41(10), 1403-1409. doi:10.1016/0277-9536(95)00112-k
[3]
Ganz, P. A., Lee, J. J., & Siau, J. (1991). Quality of life assessment. An independent prognostic variable for survival in lung cancer. Cancer, 67(12), 3131-3135. doi:10.1002/1097-0142(19910615)67:123.0.co;2-4
[4]
National Institutes of Health State-of-the-Science Conference Statement: Symptom Management in Cancer: Pain, Depression, and Fatigue, July 15-17, 2002. (2003). JNCI Journal of the National Cancer Institute, 95(15), 1110-1117. doi:10.1093/jnci/djg014

Feedback would be greatly appreciated, thank you! Jenjhayashi (talk) 14:51, 28 July 2016 (UTC)

I think addition of a short section would be a good idea. Ideally an article of cancer and depression as well - we don't seem to have one. I expect you are aware of WP:MEDRS, which should be followed. Johnbod (talk) 02:23, 30 July 2016 (UTC)

Great, thanks. I am aware of the standards and I believe my sources follow them. I pasted a draft of my contribution - although I still have to add my citations. Feedback is again, appreciated.

Jenjhayashi (talk) 12:34, 30 July 2016 (UTC)

After reviewing yours:

What recommendations would you make for revision and improvement? - Maybe add what kind of mental health you are specifically referring too, only because mental health is super broad. - Also you need to site after the statements in your paragraph since it seems like you used statistical information from sources.

More sources? - I know you are already adding more sources so thats good.

Different sources? - I don't think different sources are needed, you seem to be on track with what you want to talk about.

More background information? - I know you know this but when you add more sources add in key facts or unbiased statements along with the source.

BreeanaKoemans (talk) 15:10, 30 July 2016 (UTC)BreeanaKoemand (talk) 9:10am, 30 July 2016 (UTC)

Cancer#Causes

Arbitrary break - Etiology vs. Pathogenesis?

Arbitrary break: some MEDRS considerations

Arbitrary break: pertinent MEDRS

Chemicals

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