The Abortion-Breast Cancer Link

My professional life has been spent mostly in the academic world. For much of my time, that world held without reservation to letting evidence take a researcher to whatever conclusion the data seemed to demand, and that the conclusion could be voiced without fear of discrimination. Regrettably, times have changed somewhat.

Certain conclusions are now seen as inappropriate rather than merely unsubstantiated. In some fields, a researcher who feels led by her or his research to take a position can fear being attacked for their motives rather than their research skills. Climate-gate is a stellar example.

An area that has puzzled me greatly along those lines is the alleged abortion-breast cancer (ABC) link. Dozens of studies have substantiated this risk, but none of the relevant authorities will admit to it. Breast cancer is not merely an academic discussion for me. It took my mother at age 59, as well as two of her sisters. A third sister is a survivor. In the past 18 months, three of my sisters-in-law have also contracted this potentially deadly disease.

If you were to look up the alleged abortion-breast cancer (or ABC) link in that well-known resource Wikipedia, you would read this:

The abortion-breast cancer hypothesis posits that induced abortion increases the risk of developing breast cancer. This position contrasts with the scientific consensus that abortion does not cause breast cancer.

The Canadian Woman’s Health Network recommends an article published by the Childbirth by Choice Trust that outlines the medical debate concerning the possible link between abortion and the development of breast cancer later in life. It summarizes the results of recent studies showing no credible link between the two.

The Canadian Cancer Society says this:

At the present time, the body of scientific evidence does not support an association between abortion and increased breast cancer risk.

We base this perspective on the findings from a workshop of over 100 of the world’s leading experts who study pregnancy and breast cancer risk. The workshop was organized by the US National Cancer Institute and it took place in 2003. The experts reviewed existing human and animal studies on the relationship between pregnancy and breast cancer risk. Among their conclusions were:
• Induced abortion is not associated with an increase in breast cancer risk
• Spontaneous abortion (miscarriage) is not associated with an increase in breast cancer risk

By the way, the American Cancer Society makes the identical claim, also referencing this 2003 study, among others.

You might conclude from this that there is no link between the procurement of an abortion and an increased risk of breast cancer. When Abbotsford Right to Life sponsored a public lecture on the abortion-breast cancer link a couple of years ago, our local university student newspaper had as a headline on the front page, “The Myth of the Abortion-Breast Cancer Link”.

But I want to explore a little further the reference by the Canadian and American Cancer Societies to the conclusive 2003 workshop that is the basis of their opinion. Here is a summary of that workshop:

In February 2003, Dr. Louise Brinton, the National Cancer Institute's chief of the Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, served as chairperson at an NCI workshop in Bethesda, MD, to assess whether abortion was implicated as a breast cancer risk.

In the opinion of "over 100 of the world's leading experts," said the subsequent NCI report, including Dr. Brinton, the answer was no....

At the time, 29 out of 38 studies conducted worldwide over 40 years showed an increased ABC risk, but NCI workshop experts nevertheless concluded it was "well established" that "induced abortion is not associated with an increase in breast cancer risk."

It should be pointed out that none of the authors of the 29 studies that did find a link of anywhere from 30% to 100% were invited to that workshop.

But then a funny thing happened. In April 2009 that same chairperson, Dr. Brinton, co-authored a research paper published in the prestigious journal Cancer Epidemiology, Biomarkers and Prevention, which concluded that the risk of a particularly deadly form of breast cancer that attacks women under 40 raises 40 percent if a woman has had an abortion.

Now a cancer society “insider” had found the missing link.

The Toronto Globe and Mail wrote to the NCI on Jan. 8/09 and reported the results of their correspondence as follows:

An e-mail to Dr. Brinton on Friday was returned by an Institute spokesman named Michael Miller who said: "NCI has no comment on this study. Our statement and other information on this issue can be found at http://www.cancer.gov/cancertopics/ere." That link turns up [the] 2003 document that says a workshop of more than 100 leading experts concluded that having an abortion or miscarriage does not increase a woman's subsequent risk of developing breast cancer.

Requests for an explanation of the apparent discrepancy between that position and the information contained in the study released last spring went unanswered by NCI…

The Globe concluded:
[T]rying to prevent abortions by scaring women with breast cancer would truly be wrong. But so too would be suppressing the risks of abortion or any medical procedure.

But if you go to the NCI website, you will see no reference to Dr. Brinton’s 2009 article, nor does she refer to it herself in the list of research interests on her personal page. NCI continues to hide the remarkable conclusions of the study of one of its own decorated scientists. She herself has never repudiated the results, but she doesn’t promote them either.

The Liberal Party of Canada would prefer that they remain deep-sixed as well. When Conservative MP Maurice Vellacott referred to the issue and the Globe and Mail’s coverage recently, the Liberals' Status of Women critic Anita Neville was quick to call on Prime Minister Stephen Harper to silence Vellacott for his supposedly "false and misleading" statements. In a media release, Neville claimed Vellacott had denigrated "women and their rights and freedoms, adding "enough is enough . . . women deserve better from their elected representatives."

By the way, a 40% increase in risk is not considered to be particularly high. But to put things into context, governments and cancer agencies have done everything they can to reduce our exposure to second-hand tobacco smoke in order to protect us from contracting cancer. The increased risk of cancer from second-hand tobacco smoke is 20 - 30% according to that self-same NCI.

But consider the way second-hand smoke risk is dealt with compared to the higher-risk associated with abortion.

A report from the California Environmental Protection Agency in 2005 concluded that the evidence regarding secondhand smoke and breast cancer is "consistent with a causal association" in younger women. This means that the secondhand smoke acts as if it could be a cause of breast cancer in these women. The 2006 U.S. Surgeon General's report, The Health Consequences of Involuntary Exposure to Tobacco Smoke, found that there is "suggestive but not sufficient" evidence of a link at this point. In any case, women should be told that this possible link to breast cancer is yet another reason to avoid being around secondhand smoke. My source for this information? --The American Cancer Society.

Susan Martinuk, writing about the Brinton article in the January 29, 2010 edition of the Calgary Herald, added this comment:

The topic of breast cancer has long been a media darling and, consequently, there's been no shortage of reports on the plethora of new medical discoveries that are constantly shifting the rules for preventing, diagnosing and treating this disease. We're told about coffee, chocolate and wine; and the usefulness (or not) of mammograms and the harms (or not) of hormone replacement therapy. But this urgent need to keep women informed and up-to-date on the latest research suddenly dissipates if it means turning a critical eye to the sacred cow of abortion.