See Talk:Brassiere#Bras and Cancer Risk for previous discussion
One very plausible theory that explains the world-wide epidemiology of breast cancer has to do with the use of bras. Please see this link as well as the long discussion on the brassiere talk page. I know this is controversial but I think it deserves to be mentioned in the article. -- Jonathan108 ( talk) 17:17, 15 March 2008 (UTC)
The Cancer Society says: "There are no scientifically valid studies that show a correlation between wearing bras of any type and the occurrence of breast cancer. Two anthropologists made this association in a book called Dressed to Kill. Their study was not conducted according to standard principles of epidemiological research and did not take into consideration other variables, including known risk factors for breast cancer. There is no other, credible research to validate this claim in any way".
I would like to point out that this statement does not cite any evidence refuting the claim. It simply questions the study's methodology. So, there seems no basis for saying that bras pose "little or no risk." -- Jonathan108 ( talk) 01:17, 21 March 2008 (UTC)
One more thing. The "known risk factors" mentioned in the quote include breast size and obesity, both of which are obviously correlated with bra use. If the bra theory is true, these "known" factors would suddenly become suspect. This would be great news, since bra use is avoidable, while breast size usually is not.
It would be easy to design a study that distinguishes the factors by comparing women with similar breast sizes who wear their bras 24 hrs. per day with those who wear their bras 12 hrs. or less per day. It will just take some researchers willing to think outside the box. -- Jonathan108 ( talk) 19:50, 21 March 2008 (UTC)
"All truth goes through three stages. First it is ridiculed. Then it is violently opposed. Finally, it is accepted as self-evident." - Arthur Schoepenhauer -- Jonathan108 ( talk) 20:19, 21 March 2008 (UTC)
[Comment deleted by author, because Mastcell's above comment was added out of sequence]
1. I am referring to Wikipedia:Neutral point of view. Please read: All Wikipedia articles and other encyclopedic content must be written from a neutral point of view, representing fairly, and as far as possible without bias, all significant views that have been published by reliable sources. This is non-negotiable and expected of all articles and all editors.
2. That there is a correlation (causative or not, that´s another issue) between bras and Breast cancer is NOT a fringe theory. It is a scientific fact published in reliable sources.
3. I have no "definitive conclusion" about this issue. Moreover: What editors think about this or that is totally irrelevant here. I beg you to stop mentioning what you think I think. It is a waste of time to argue about this.
4. Three institutions (two of them just private institutions) from the USA (a Canadian or Chilean institution is also "American") make not a "mainstream view", much less make two scientific studies published by WP:RS a "fringe theory".
5. Breastcancer.org and American Cancer Society are just two private institutions. I frankly fail to see how the opinion of two private institutions can make "fringe" the results of two scientific studies publised in reliable sources. Please explain how is that possible. Moreover: The American Cancer Society posts patently incorrect information, as I showed above.
6. Seems that "your" sources "know" that there is no link (causative or otherwise) between bras and breast cancer. Could you please explain us HOW do they "know"?. In Science knowledge comes from experiments/studies. Where are those studies, please?. Or their "knowledge" is just their say-so?. If affirmative: Could you please explain us how a say-so can make "fringe" two scientific studies?.
7. WP:OR is irrelevant in this discussion. "My" sources are good according to WP:RS.
8. I do not want (of course) to write in the article that "bras cause cancer". I want to add something like this:
Thank you very much for expressing your thoughts.
My comments:
True. Could you please tell us where do you think that piece of information belongs in Wikipedia.
I can not be "sure" about the content of a paper I have not read (How could I be?). That´s obvious. In fact I have never suggested that study hinted at a link between breast cancer and bras. I brougth the link to that study here just because -whatever its content- it is relevant to this issue.
Excuse me, I quote from [7]:
This is NOT a "weak correlation". This is a very strongBold text one. Of course that correlation is not a proof of causation.
I ask you the same question again: Where is the place at Wikipedia for this STRONG correlation?.
AFAIAC that article does not exist, unless someone tells me how I can gain access to it. How can I comment an article I can not read?.
I have never typed in my life the sentence "bras cause cancer" (now I just had). Please read Straw man.
The Chinese scientists mentioned do not wearing a bra at night as a protective factor against cancer. The guys at Harvard (Hsieh et alii) wrote "Premenopausal women who do not wear bras had half the risk of breast cancer compared with bra users". I want to know where is the place at Wikipedia to add these facts. That´s all.
Uh. You are completely right: American (word). Thank you for improving my knowledge of the English language.
Two private organizations do not create a mainstream. They much less cancel two scientific studies.
Plase read:
I do not need to resort to editor´s opinions. There is a very clear Wikipedia policy that settles the issue: Unless someone can produce a Reliable Source stating that there is a consensus about this matter, no consensus exists for us here.
I try to assume nothing. My English teacher told us a tongue-in-cheek "ethymology" of the word assume you probably know about.
Anyway, according to Wikipedia policies "my" sources are higher quality than yours. Please read:
Finally, MastCell wrote:
As a Wikipedia editor, I am not considering those points ("bad life incidence" or "prophylactic") now. Now I am only considering the issue of bras.
If the wording of the chinese study abstract sounds strange to you, that´s fine. I am not going to discuss that wording. The guys who indexed that study are a valid source according to WP:RS, and that´s my point.
Seems we can not reach a consensus here as editors. Sorry for the inconvenience. MastCell, you have a lot of experience. What do you suggest? Randroide ( talk) 17:31, 28 October 2009 (UTC)
The article shows the section "Age" to be followed immediately by the section "Heredity", but when I proceeded to edit the section "Age" I found it to be followed immediately by another section, "Gender". I studied the text in the article and the code in the edit box, and I discovered an apparent error located between "functional impairment." and "Men with gynaecomastia". The code "<ref name="Perkins 2007">" is not followed by "</ref>" before the next occurrence of "<ref>". I do not know enough about editing references or about the data for this reference to correct this error, so I am placing this information here to alert someone who can make the correction.
dubious – discuss Several citations to unreliable source, paragraphs are copies of each other. Nutriveg ( talk) 17:44, 14 December 2008 (UTC)
The current name of this article (Epidemiology and etiology of breast cancer) is misleading. Epidemiology in this case rather would be the study field of the risk factors, and its use here is probably confusing for most readers. Etiology is also confusing here, since only ~5% of breast cancers have a specific genetic cause. The rest is a product of risk factors. Indeed, the whole article currently almost exclusively about risk factors. Therefore, I now rename it. Mikael Häggström ( talk) 14:18, 18 September 2009 (UTC)
Why did you remove "Ovary removal"/"Ovary oblation" and Insulin? This is a medical article, please follow WP:MEDRS and avoid using websites.-- Nutriveg ( talk) 17:16, 18 September 2009 (UTC)
A claim was recently made on this page for iodine deficiency as a risk factor for breast cancer. There's very little work in humans to support this, and relevant scholarly articles make much smaller claims, like 'women with breast cancer have more autoimmune thyroid disease than women without breast cancer' -- but without making any claims about causation. (Also, please notice that "autoimmune thyroid disease" is not exactly iodine deficiency.) Most of these articles are also old by our standards. I don't think that iodine deficiency should be listed unless we can get at least one really solid, mainstream, scholarly source that directly says that iodine deficiency is a risk factor. WhatamIdoing ( talk) 20:44, 16 May 2010 (UTC)
Why is "Iodine deficiency" in the section "Environmental factors" rather than "Diet"? Should it go next to "Iodolipids"? Norman21 ( talk) 20:54, 18 May 2010 (UTC)
I suggest that editors read this very accessible review of that dubious "journal". WhatamIdoing ( talk) 20:56, 18 May 2010 (UTC)
Sorry to jump in so late, but it should really have been called epidemiology rather than "risk factors". Factors like mammographic density, age, gender fit much better into epidemiology than pass as risk factors. Richiez ( talk) 16:13, 15 September 2010 (UTC)
The tobacco stuff is out of date. It turns out that the "suggestive" link to tobacco disappears once you control for alcohol consumption. I've mislaid the source for the moment, but this comment is an aide mémoire to make sure we get that fixed. WhatamIdoing ( talk) 17:47, 18 April 2011 (UTC)
Someone smarter than I should add a synopsis of the findings in this important study to the discussion: http://jeffreydach.com/files/80618-70584/Unequal_Risks_Breast_Cancer_hormone_replacement_E3N_cohort_study_Fournier.pdf 75.201.193.168 ( talk) 17:36, 13 July 2011 (UTC)
This is a significant issue that needs to be more closely examined with a NPOV. Given the increadibly large number of women taking hormonal contraceptives and the as yet undetermined reason for continued increase in breast cancer, as a scientific community, we need to keep on open mind toward all potential causes. We need to be careful that we are not unduly swayed by the position statements of various groups who tout themselves as experts who tend to downplay an association of hormonal contraception and breast cancer. The 1996 study has flaws that Khalenborn's study addresses quite well as was included my edit with 2 additional references (in addition to Kahlenborn's Mayo Clinic study).
Mastcell stated "It seems to me to ignore a large portion of available evidence and expert opinion in the field." However, I didn't delete the prior commentary on the 1996 British study so as to allow it and its commentary to stand on its own merit. I think an objection(NPO) approach would be to leave it as my last edit did which presents the key finding of each study and supporting/referrenced commentary. If additional studies specifically point out methodological flaws or problems with another study (Kahlenborn's for example), then we can add it too and let it stand on its own.
Finally, we need to be careful of ad hominum attacks against investigators who have published material challenging what had previously been considered conventional wisdom. Describing someone as an "anti-abortion activist" is no more relevant to the data than whether or not he or she voted for Obama in the last election. Would you tolerate an editor discrediting references because of accusations that the primary author is a "pro-abortion activist,"? In many areas wikipedia has been able to rise above political, financial, and ideologic special interests. Whether it's Kahlenborn's research on contraception of Brind's on abortion, we should assume good faith in their work and consider it as objectively and openly as any other. No person or group is going to be completely free of bias, in fact the larger and more powerful the organizations are that promote one angle and interpretation, the more likely we should be willing to consider the counterargument and give voice to their valid findings. Nothing less than the physical health and well-being of millions of women is at stake hear. Evidence of a link between hormonal contraception and breast cancer is a mightily inconvenient truth if one is a deeply committed "pro-pill activist." However, in the final analysis we must ask ourselselves: what is more important? The good name of hormonal contraception or the health of women? Frankgyn 03:51, 22 March 2012 (UTC) — Preceding unsigned comment added by Frankgyn ( talk • contribs)
Let's talk about ad hominems. There is a difference between an ad hominem and a legitimate concern over conflict of interest. Again, you try to have it both ways: you point to drug-company funding to discredit findings you disagree with, but you take umbrage at similar concerns when they're directed at your one favored source (the 2006 Kahlenborn paper, PMID 17036554). When drug companies fund research, that funding is disclosed for a reason - because it's vital to help the reader weigh the evidence, and because considering conflicts of interest is not an "ad hominem" fallacy, but an important part of critical reading.
Let's talk sources. Why, again, should we feature Kahlenborn's 2006 paper to the exclusion of virtually all other sources? What about material from major expert bodies, like the National Cancer Institute? What about more recent literature? There have been many review articles on the topic since 2006, including:
MastCell, thank you for the thoughtful feedback. To clarify, I never intended my statement to "keep an open mind toward all potential causes," and "to be careful that we are not unduly swayed by the position statements of various groups" to mean that we should "disregard the opinions of expert groups" as you suggest. It's not about one paper that I personally favor, it's about a willingness to consider compelling data on its own merit. I will review the more recent studies you have graciously listed. Do any of them address the methodology or findings of the Kahlenborn paper?
As for " ad hominem" (thanks for the spelling correction, by the way), I agree with you that there is an important difference between personal attacks (i.e. he's a anti-abortion activist implying that therefore we can't trust him) and legitimate conflicts of interest (as in the case of large corporate bodies with substantial funding from the pharmaceutical industry who have a clear vested interest in publishing data in support of their products). An ad hominem (Latin "to the person") fallacy involves the attack of an individual person (again "anti-abortion"), not so much applicable to an institution/organization , whereas " conflict of interest" occurs when an individual or organization is involved in multiple interests, one of which could possibly corrupt the motivation for an act in the other." (wiki definition). I don't doubt the sincerity of your interest in objective truth (and I trust you don't doubt mine either). However, I think in this venue, we need be especially careful about ad hominem attacks as well as conflicts of interest (COI) problems. For example, if you can make a case that Kahlenborn has a COI, in his research, by all means do so and we can engage in a healthy debate on that point.
I'll play devil's advocate: Do you think his personal opposition to the current legal status of abortion motivates him to show a connection to contraception and breast cancer? If so, should we be be investigating every one else's personal beliefs about abortion as a sort of litmus test before citing their work?--Frankgyn 16:16, 22 March 2012 (UTC) — Preceding unsigned comment added by Frankgyn ( talk • contribs)
Secondly, I think there is a distinction between the roles of researcher and advocate. In a field with political ramifications, one can still often distinguish between people who are researchers first and advocates second, vs. those who are primarily advocates and whose research efforts are limited to the service of their advocacy. Of course, this distinction is somewhat subjective, and largely for that reason I think you're right that this isn't a particularly productive road to go down in this setting.
Moving on to more concrete territory... to address your question about whether later meta-analyses cite and/or address Kahlenborn's findings: the 2010 review ( PMID 20543200, full text) commented that the Kahlenborn study "used only case–control studies and crude odd ratio (not adjusted), which could have increased the RR [relative risk] values."
I'd be interested to know what you think: given that a number of large studies have been published subsequent to the 2006 Kahlenborn paper (generally showing no association between oral contraceptives and breast cancer risk), and given that more recent review articles conclude that "in a majority of studies there is no increase in the risk of breast cancer reported in OC users", how should we accurately convey up-to-date medical opinion to the reader? MastCell Talk 21:00, 22 March 2012 (UTC)
I hope that we can at least agree to some mutual acknowledgement that hormonal contraceptives do increase the risk of breast cancer, while also simultaneously agreeing that the exact degree of increased riks is indeed debatable with different studies showing varying results. In this vain, I also believe we should replace the WHO statement removed by Roscelese. The readers (women especially) are entitled to a fair representation of range of data available to date. Perhaps a statement on the WHO positions could be clarified that the initial "Group 1" desisgnation to OC's was first assigned in 1999 (when I believed HRT was also evaluated), and then re-affirmed in 2005. Frankgyn ( talk) 22:14, 23 March 2012 (UTC)
I'm not sure that emphasizing the WHO classification is the best way to inform the reader. The WHO classifications don't address the risk-benefit balance of specific medications. After all, oral contraceptives are clearly powerful anti-carcinogens when it comes to, say, ovarian cancer. And the effect of oral contraception on overall cancer risk is neutral to possibly slightly beneficial. At least some groups have expressed the view that WHO carcinogen ratings have no clinical relevance whatsoever (e.g. PMID 18335326). From a real-world perspective, there is no evidence that oral contraceptives increase the overall cancer risk, so highlighting them as "carcinogens" runs the risk of misinforming by omission. MastCell Talk 22:47, 23 March 2012 (UTC)
I have to agree with WhatamIdoing on her point. If the evidence that HRT (whose estrogen and progesterone levels are much lower than even the lowest dose OCP's) was found to be so harmful that the WHI had to be ended early, it would certainly seem biologically plausible that the much higher doses of estrogen and progesterone of more synthetic varieties would carry substantial risk for increased breast cancer. Mastcell, the article you stated that dismisses the validity or applicability of the WHO carcinogen lists loses all credibility in the following quote from their abstract: "Equating natural compounds like estradiol with defined carcinogens like asbestos..." The inexcusable misrepresentation here is that the hormonal components of OCP's are human-identical molecules. If we are making appeals to expert groups, I think we should be more willing to give ear and print reporting of the findings of this body whose work in this area is to advise the international public of well-established carcinogenic compounds. If saw dust is on that list, I'll be more careful to where a mask to prevent inhaling such. If salty fish in on the list, I'd do well to minimize or avoid consumption of excess salt in preserved fish. As for the ovarian cancer vs breast cancer issue. We need to seriously look at the whole picture and take into consideration how much higher the incidence of breast cancer is than ovarian cancer. Furthermore, we need to consider the increased risk of cervical cancer and liver cancer associated with OCP's while factoring in the decreased risk of uterine cancer. The last time I reviewed such data, the net result leaning heavily in the net increase in cancer--owing in large part to the already high baseline incidence of breast cancer. Frankgyn ( talk) 02:09, 24 March 2012 (UTC)
As for your last sentence: when was the last time you reviewed the data? There is absolutely no evidence that modern oral contraceptives increase overall cancer risk in Western populations. As far as I'm aware, no reputable expert body holds such a position. The largest and most recent study to address the question (Hannaford et al., BMJ 2007, PMID 17855280) found the opposite: an absolute reduction in overall cancer risk in women who used OCPs. Their data suggest that for every 10,000 women who use OCPs, between 10 and 45 cases of cancer will be prevented.
Nor is there any evidence - at all - that modern oral contraceptives increase a woman's risk of dying. Again, if anything, the opposite appears to be true: mortality is generally lower among OCP users. See Hannaford et al., BMJ 2010 ( PMID 20223876); Vessey et al., Lancet 2003 ( PMID 12885478); Colditz, Annals of Internal Medicine 1994 ( PMID 8154642); and so forth. There is a well-known risk to women over 35 who smoke, and these women aren't typically prescribed OCPs, but in the general population I'll reiterate that data do not show an increased risk of cancer overall, nor of death, in OCP users, and may show a benefit for both outcomes. I'm a bit concerned that we're cherry-picking superficially alarming factoids at the expense of providing a thorough and accurate overview of the topic. MastCell Talk 05:44, 24 March 2012 (UTC)
The most obvious risk factor for breast cancer (besides female sex and having breasts, and right up there with family history) is country of residence. In north and west Europe, age-standardized incidence is in the order of ten times that of south and east Asia. There is even a ASI gradient across Europe, from West to East. The importance of environmental factors is shown in the migration effect, in that a woman migrating at a young age from low- to high-incidence countries acquires the local risk over a period of decades. Geographical and temporal clustering or changes in risk, with migration effects are telling us that there is an important environmental factor. — Preceding unsigned comment added by 74.12.30.133 ( talk) 15:53, 26 May 2013 (UTC)
See Talk:Brassiere#Bras and Cancer Risk for previous discussion
One very plausible theory that explains the world-wide epidemiology of breast cancer has to do with the use of bras. Please see this link as well as the long discussion on the brassiere talk page. I know this is controversial but I think it deserves to be mentioned in the article. -- Jonathan108 ( talk) 17:17, 15 March 2008 (UTC)
The Cancer Society says: "There are no scientifically valid studies that show a correlation between wearing bras of any type and the occurrence of breast cancer. Two anthropologists made this association in a book called Dressed to Kill. Their study was not conducted according to standard principles of epidemiological research and did not take into consideration other variables, including known risk factors for breast cancer. There is no other, credible research to validate this claim in any way".
I would like to point out that this statement does not cite any evidence refuting the claim. It simply questions the study's methodology. So, there seems no basis for saying that bras pose "little or no risk." -- Jonathan108 ( talk) 01:17, 21 March 2008 (UTC)
One more thing. The "known risk factors" mentioned in the quote include breast size and obesity, both of which are obviously correlated with bra use. If the bra theory is true, these "known" factors would suddenly become suspect. This would be great news, since bra use is avoidable, while breast size usually is not.
It would be easy to design a study that distinguishes the factors by comparing women with similar breast sizes who wear their bras 24 hrs. per day with those who wear their bras 12 hrs. or less per day. It will just take some researchers willing to think outside the box. -- Jonathan108 ( talk) 19:50, 21 March 2008 (UTC)
"All truth goes through three stages. First it is ridiculed. Then it is violently opposed. Finally, it is accepted as self-evident." - Arthur Schoepenhauer -- Jonathan108 ( talk) 20:19, 21 March 2008 (UTC)
[Comment deleted by author, because Mastcell's above comment was added out of sequence]
1. I am referring to Wikipedia:Neutral point of view. Please read: All Wikipedia articles and other encyclopedic content must be written from a neutral point of view, representing fairly, and as far as possible without bias, all significant views that have been published by reliable sources. This is non-negotiable and expected of all articles and all editors.
2. That there is a correlation (causative or not, that´s another issue) between bras and Breast cancer is NOT a fringe theory. It is a scientific fact published in reliable sources.
3. I have no "definitive conclusion" about this issue. Moreover: What editors think about this or that is totally irrelevant here. I beg you to stop mentioning what you think I think. It is a waste of time to argue about this.
4. Three institutions (two of them just private institutions) from the USA (a Canadian or Chilean institution is also "American") make not a "mainstream view", much less make two scientific studies published by WP:RS a "fringe theory".
5. Breastcancer.org and American Cancer Society are just two private institutions. I frankly fail to see how the opinion of two private institutions can make "fringe" the results of two scientific studies publised in reliable sources. Please explain how is that possible. Moreover: The American Cancer Society posts patently incorrect information, as I showed above.
6. Seems that "your" sources "know" that there is no link (causative or otherwise) between bras and breast cancer. Could you please explain us HOW do they "know"?. In Science knowledge comes from experiments/studies. Where are those studies, please?. Or their "knowledge" is just their say-so?. If affirmative: Could you please explain us how a say-so can make "fringe" two scientific studies?.
7. WP:OR is irrelevant in this discussion. "My" sources are good according to WP:RS.
8. I do not want (of course) to write in the article that "bras cause cancer". I want to add something like this:
Thank you very much for expressing your thoughts.
My comments:
True. Could you please tell us where do you think that piece of information belongs in Wikipedia.
I can not be "sure" about the content of a paper I have not read (How could I be?). That´s obvious. In fact I have never suggested that study hinted at a link between breast cancer and bras. I brougth the link to that study here just because -whatever its content- it is relevant to this issue.
Excuse me, I quote from [7]:
This is NOT a "weak correlation". This is a very strongBold text one. Of course that correlation is not a proof of causation.
I ask you the same question again: Where is the place at Wikipedia for this STRONG correlation?.
AFAIAC that article does not exist, unless someone tells me how I can gain access to it. How can I comment an article I can not read?.
I have never typed in my life the sentence "bras cause cancer" (now I just had). Please read Straw man.
The Chinese scientists mentioned do not wearing a bra at night as a protective factor against cancer. The guys at Harvard (Hsieh et alii) wrote "Premenopausal women who do not wear bras had half the risk of breast cancer compared with bra users". I want to know where is the place at Wikipedia to add these facts. That´s all.
Uh. You are completely right: American (word). Thank you for improving my knowledge of the English language.
Two private organizations do not create a mainstream. They much less cancel two scientific studies.
Plase read:
I do not need to resort to editor´s opinions. There is a very clear Wikipedia policy that settles the issue: Unless someone can produce a Reliable Source stating that there is a consensus about this matter, no consensus exists for us here.
I try to assume nothing. My English teacher told us a tongue-in-cheek "ethymology" of the word assume you probably know about.
Anyway, according to Wikipedia policies "my" sources are higher quality than yours. Please read:
Finally, MastCell wrote:
As a Wikipedia editor, I am not considering those points ("bad life incidence" or "prophylactic") now. Now I am only considering the issue of bras.
If the wording of the chinese study abstract sounds strange to you, that´s fine. I am not going to discuss that wording. The guys who indexed that study are a valid source according to WP:RS, and that´s my point.
Seems we can not reach a consensus here as editors. Sorry for the inconvenience. MastCell, you have a lot of experience. What do you suggest? Randroide ( talk) 17:31, 28 October 2009 (UTC)
The article shows the section "Age" to be followed immediately by the section "Heredity", but when I proceeded to edit the section "Age" I found it to be followed immediately by another section, "Gender". I studied the text in the article and the code in the edit box, and I discovered an apparent error located between "functional impairment." and "Men with gynaecomastia". The code "<ref name="Perkins 2007">" is not followed by "</ref>" before the next occurrence of "<ref>". I do not know enough about editing references or about the data for this reference to correct this error, so I am placing this information here to alert someone who can make the correction.
dubious – discuss Several citations to unreliable source, paragraphs are copies of each other. Nutriveg ( talk) 17:44, 14 December 2008 (UTC)
The current name of this article (Epidemiology and etiology of breast cancer) is misleading. Epidemiology in this case rather would be the study field of the risk factors, and its use here is probably confusing for most readers. Etiology is also confusing here, since only ~5% of breast cancers have a specific genetic cause. The rest is a product of risk factors. Indeed, the whole article currently almost exclusively about risk factors. Therefore, I now rename it. Mikael Häggström ( talk) 14:18, 18 September 2009 (UTC)
Why did you remove "Ovary removal"/"Ovary oblation" and Insulin? This is a medical article, please follow WP:MEDRS and avoid using websites.-- Nutriveg ( talk) 17:16, 18 September 2009 (UTC)
A claim was recently made on this page for iodine deficiency as a risk factor for breast cancer. There's very little work in humans to support this, and relevant scholarly articles make much smaller claims, like 'women with breast cancer have more autoimmune thyroid disease than women without breast cancer' -- but without making any claims about causation. (Also, please notice that "autoimmune thyroid disease" is not exactly iodine deficiency.) Most of these articles are also old by our standards. I don't think that iodine deficiency should be listed unless we can get at least one really solid, mainstream, scholarly source that directly says that iodine deficiency is a risk factor. WhatamIdoing ( talk) 20:44, 16 May 2010 (UTC)
Why is "Iodine deficiency" in the section "Environmental factors" rather than "Diet"? Should it go next to "Iodolipids"? Norman21 ( talk) 20:54, 18 May 2010 (UTC)
I suggest that editors read this very accessible review of that dubious "journal". WhatamIdoing ( talk) 20:56, 18 May 2010 (UTC)
Sorry to jump in so late, but it should really have been called epidemiology rather than "risk factors". Factors like mammographic density, age, gender fit much better into epidemiology than pass as risk factors. Richiez ( talk) 16:13, 15 September 2010 (UTC)
The tobacco stuff is out of date. It turns out that the "suggestive" link to tobacco disappears once you control for alcohol consumption. I've mislaid the source for the moment, but this comment is an aide mémoire to make sure we get that fixed. WhatamIdoing ( talk) 17:47, 18 April 2011 (UTC)
Someone smarter than I should add a synopsis of the findings in this important study to the discussion: http://jeffreydach.com/files/80618-70584/Unequal_Risks_Breast_Cancer_hormone_replacement_E3N_cohort_study_Fournier.pdf 75.201.193.168 ( talk) 17:36, 13 July 2011 (UTC)
This is a significant issue that needs to be more closely examined with a NPOV. Given the increadibly large number of women taking hormonal contraceptives and the as yet undetermined reason for continued increase in breast cancer, as a scientific community, we need to keep on open mind toward all potential causes. We need to be careful that we are not unduly swayed by the position statements of various groups who tout themselves as experts who tend to downplay an association of hormonal contraception and breast cancer. The 1996 study has flaws that Khalenborn's study addresses quite well as was included my edit with 2 additional references (in addition to Kahlenborn's Mayo Clinic study).
Mastcell stated "It seems to me to ignore a large portion of available evidence and expert opinion in the field." However, I didn't delete the prior commentary on the 1996 British study so as to allow it and its commentary to stand on its own merit. I think an objection(NPO) approach would be to leave it as my last edit did which presents the key finding of each study and supporting/referrenced commentary. If additional studies specifically point out methodological flaws or problems with another study (Kahlenborn's for example), then we can add it too and let it stand on its own.
Finally, we need to be careful of ad hominum attacks against investigators who have published material challenging what had previously been considered conventional wisdom. Describing someone as an "anti-abortion activist" is no more relevant to the data than whether or not he or she voted for Obama in the last election. Would you tolerate an editor discrediting references because of accusations that the primary author is a "pro-abortion activist,"? In many areas wikipedia has been able to rise above political, financial, and ideologic special interests. Whether it's Kahlenborn's research on contraception of Brind's on abortion, we should assume good faith in their work and consider it as objectively and openly as any other. No person or group is going to be completely free of bias, in fact the larger and more powerful the organizations are that promote one angle and interpretation, the more likely we should be willing to consider the counterargument and give voice to their valid findings. Nothing less than the physical health and well-being of millions of women is at stake hear. Evidence of a link between hormonal contraception and breast cancer is a mightily inconvenient truth if one is a deeply committed "pro-pill activist." However, in the final analysis we must ask ourselselves: what is more important? The good name of hormonal contraception or the health of women? Frankgyn 03:51, 22 March 2012 (UTC) — Preceding unsigned comment added by Frankgyn ( talk • contribs)
Let's talk about ad hominems. There is a difference between an ad hominem and a legitimate concern over conflict of interest. Again, you try to have it both ways: you point to drug-company funding to discredit findings you disagree with, but you take umbrage at similar concerns when they're directed at your one favored source (the 2006 Kahlenborn paper, PMID 17036554). When drug companies fund research, that funding is disclosed for a reason - because it's vital to help the reader weigh the evidence, and because considering conflicts of interest is not an "ad hominem" fallacy, but an important part of critical reading.
Let's talk sources. Why, again, should we feature Kahlenborn's 2006 paper to the exclusion of virtually all other sources? What about material from major expert bodies, like the National Cancer Institute? What about more recent literature? There have been many review articles on the topic since 2006, including:
MastCell, thank you for the thoughtful feedback. To clarify, I never intended my statement to "keep an open mind toward all potential causes," and "to be careful that we are not unduly swayed by the position statements of various groups" to mean that we should "disregard the opinions of expert groups" as you suggest. It's not about one paper that I personally favor, it's about a willingness to consider compelling data on its own merit. I will review the more recent studies you have graciously listed. Do any of them address the methodology or findings of the Kahlenborn paper?
As for " ad hominem" (thanks for the spelling correction, by the way), I agree with you that there is an important difference between personal attacks (i.e. he's a anti-abortion activist implying that therefore we can't trust him) and legitimate conflicts of interest (as in the case of large corporate bodies with substantial funding from the pharmaceutical industry who have a clear vested interest in publishing data in support of their products). An ad hominem (Latin "to the person") fallacy involves the attack of an individual person (again "anti-abortion"), not so much applicable to an institution/organization , whereas " conflict of interest" occurs when an individual or organization is involved in multiple interests, one of which could possibly corrupt the motivation for an act in the other." (wiki definition). I don't doubt the sincerity of your interest in objective truth (and I trust you don't doubt mine either). However, I think in this venue, we need be especially careful about ad hominem attacks as well as conflicts of interest (COI) problems. For example, if you can make a case that Kahlenborn has a COI, in his research, by all means do so and we can engage in a healthy debate on that point.
I'll play devil's advocate: Do you think his personal opposition to the current legal status of abortion motivates him to show a connection to contraception and breast cancer? If so, should we be be investigating every one else's personal beliefs about abortion as a sort of litmus test before citing their work?--Frankgyn 16:16, 22 March 2012 (UTC) — Preceding unsigned comment added by Frankgyn ( talk • contribs)
Secondly, I think there is a distinction between the roles of researcher and advocate. In a field with political ramifications, one can still often distinguish between people who are researchers first and advocates second, vs. those who are primarily advocates and whose research efforts are limited to the service of their advocacy. Of course, this distinction is somewhat subjective, and largely for that reason I think you're right that this isn't a particularly productive road to go down in this setting.
Moving on to more concrete territory... to address your question about whether later meta-analyses cite and/or address Kahlenborn's findings: the 2010 review ( PMID 20543200, full text) commented that the Kahlenborn study "used only case–control studies and crude odd ratio (not adjusted), which could have increased the RR [relative risk] values."
I'd be interested to know what you think: given that a number of large studies have been published subsequent to the 2006 Kahlenborn paper (generally showing no association between oral contraceptives and breast cancer risk), and given that more recent review articles conclude that "in a majority of studies there is no increase in the risk of breast cancer reported in OC users", how should we accurately convey up-to-date medical opinion to the reader? MastCell Talk 21:00, 22 March 2012 (UTC)
I hope that we can at least agree to some mutual acknowledgement that hormonal contraceptives do increase the risk of breast cancer, while also simultaneously agreeing that the exact degree of increased riks is indeed debatable with different studies showing varying results. In this vain, I also believe we should replace the WHO statement removed by Roscelese. The readers (women especially) are entitled to a fair representation of range of data available to date. Perhaps a statement on the WHO positions could be clarified that the initial "Group 1" desisgnation to OC's was first assigned in 1999 (when I believed HRT was also evaluated), and then re-affirmed in 2005. Frankgyn ( talk) 22:14, 23 March 2012 (UTC)
I'm not sure that emphasizing the WHO classification is the best way to inform the reader. The WHO classifications don't address the risk-benefit balance of specific medications. After all, oral contraceptives are clearly powerful anti-carcinogens when it comes to, say, ovarian cancer. And the effect of oral contraception on overall cancer risk is neutral to possibly slightly beneficial. At least some groups have expressed the view that WHO carcinogen ratings have no clinical relevance whatsoever (e.g. PMID 18335326). From a real-world perspective, there is no evidence that oral contraceptives increase the overall cancer risk, so highlighting them as "carcinogens" runs the risk of misinforming by omission. MastCell Talk 22:47, 23 March 2012 (UTC)
I have to agree with WhatamIdoing on her point. If the evidence that HRT (whose estrogen and progesterone levels are much lower than even the lowest dose OCP's) was found to be so harmful that the WHI had to be ended early, it would certainly seem biologically plausible that the much higher doses of estrogen and progesterone of more synthetic varieties would carry substantial risk for increased breast cancer. Mastcell, the article you stated that dismisses the validity or applicability of the WHO carcinogen lists loses all credibility in the following quote from their abstract: "Equating natural compounds like estradiol with defined carcinogens like asbestos..." The inexcusable misrepresentation here is that the hormonal components of OCP's are human-identical molecules. If we are making appeals to expert groups, I think we should be more willing to give ear and print reporting of the findings of this body whose work in this area is to advise the international public of well-established carcinogenic compounds. If saw dust is on that list, I'll be more careful to where a mask to prevent inhaling such. If salty fish in on the list, I'd do well to minimize or avoid consumption of excess salt in preserved fish. As for the ovarian cancer vs breast cancer issue. We need to seriously look at the whole picture and take into consideration how much higher the incidence of breast cancer is than ovarian cancer. Furthermore, we need to consider the increased risk of cervical cancer and liver cancer associated with OCP's while factoring in the decreased risk of uterine cancer. The last time I reviewed such data, the net result leaning heavily in the net increase in cancer--owing in large part to the already high baseline incidence of breast cancer. Frankgyn ( talk) 02:09, 24 March 2012 (UTC)
As for your last sentence: when was the last time you reviewed the data? There is absolutely no evidence that modern oral contraceptives increase overall cancer risk in Western populations. As far as I'm aware, no reputable expert body holds such a position. The largest and most recent study to address the question (Hannaford et al., BMJ 2007, PMID 17855280) found the opposite: an absolute reduction in overall cancer risk in women who used OCPs. Their data suggest that for every 10,000 women who use OCPs, between 10 and 45 cases of cancer will be prevented.
Nor is there any evidence - at all - that modern oral contraceptives increase a woman's risk of dying. Again, if anything, the opposite appears to be true: mortality is generally lower among OCP users. See Hannaford et al., BMJ 2010 ( PMID 20223876); Vessey et al., Lancet 2003 ( PMID 12885478); Colditz, Annals of Internal Medicine 1994 ( PMID 8154642); and so forth. There is a well-known risk to women over 35 who smoke, and these women aren't typically prescribed OCPs, but in the general population I'll reiterate that data do not show an increased risk of cancer overall, nor of death, in OCP users, and may show a benefit for both outcomes. I'm a bit concerned that we're cherry-picking superficially alarming factoids at the expense of providing a thorough and accurate overview of the topic. MastCell Talk 05:44, 24 March 2012 (UTC)
The most obvious risk factor for breast cancer (besides female sex and having breasts, and right up there with family history) is country of residence. In north and west Europe, age-standardized incidence is in the order of ten times that of south and east Asia. There is even a ASI gradient across Europe, from West to East. The importance of environmental factors is shown in the migration effect, in that a woman migrating at a young age from low- to high-incidence countries acquires the local risk over a period of decades. Geographical and temporal clustering or changes in risk, with migration effects are telling us that there is an important environmental factor. — Preceding unsigned comment added by 74.12.30.133 ( talk) 15:53, 26 May 2013 (UTC)