World Conference on Breast Cancer

Abortion and Breast Cancer
Positive Response To Latest Developments Presented At World Conference On Breast Cancer

by Joel Brind, PhD



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It was encouraging and somewhat surprising to have an update of our "Comprehensive review and meta-analysis" on induced abortion and breast cancer accepted for presentation at the July [1997] "World Conference on Breast Cancer" in Kingston, Ontario. The conference was organized by veteran pro-abortion activist Bella Abzug in her capacity as president of Women's Environment and Development Organization.

The original paper, which I had written in collaboration with colleagues from Penn State College of Medicine in Hershey, was published in the British Medical Association's Journal of Epidemiology and Community Health last October. My presentation in Ontario centered on several additional studies essentially confirming our original finding of 30% increased risk of breast cancer attributable to abortion. Nothing is more an article of faith for radical feminists such as Bella Abzug than that abortion is indispensable to women's equality.

Therefore I expected that the room would be largely empty -- especially given that there were five other concurrent sessions -- for such an against-the-grain presentation. But to my surprise, not only was the room full, but the attentive audience included Ms. Abzug herself.

As readers may recall, our meta-analysis found that 24 out of the 30 epidemiological studies published worldwide since 1957 have confirmed the abortion-breast cancer (ABC) link. More recent publications supporting and challenging the ABC link were discussed in my presentation in Kingston.

For one, there is the continuing heated debate about the Melbye study from Denmark published in this January's New England Journal of Medicine (NEJM). The U.S. National Cancer Institute and others continue to maintain that it disproved the ABC link. The World Conference provided me the opportunity to point out the serious flaws in the Melbye study, as had been done in an article published in National Right to Life News (5/23/97), and in a letter to the editor, which appeared in the June 19 edition of NEJM. Among other egregious flaws, Melbye et al. had misclassified some 60,000 women in the study as not having had any abortions who actually did have legal abortions on record!

For another, there was the Rookus study on Dutch women published last December in the Journal of the National Cancer Institute (JNCI). Readers may remember how the authors of this well-designed study found a 90% risk increase with abortion, but then proceeded to explain it away on the basis of something called "reporting bias".

This curious argument holds that the ABC link only appears to exist because women with breast cancer are more likely to admit having had abortions than are healthy women. As a result, they say, studies which depend on women reporting their reproductive histories (as most studies do) will show an artificially elevated risk.

The authors of the Dutch study claimed to have evidence of reporting bias. But as was demonstrated both to readers of NRL News (12/10/96) and readers of the April 12 edition of JNCI, by way of another letter to the editor, it was this so-called evidence which had been artificially manufactured.

It was the JNCI editorial that accompanied the Dutch study which the journal's editors (who are also high-ranking NCI officials) used to attack our meta-analysis by name. They claimed we had made "a leap beyond the bounds of inference" for inferring a causal link between abortion and breast cancer.

In our letter rebutting these charges, we pointed out how, rather than relying solely on the statistical link, a causal association was also supported by the biological facts, namely:

  1. "Estrogens are strong growth promoters of normal and most cancerous breast tissue.

  2. Most known risk factors for breast cancer are attributable to some form of estrogen overexposure.

  3. Maternal estradiol (estrogen) rises 20-fold (2,000%) during the first trimester of a normal pregnancy. [Estrogen makes breast tissue grow, including potentially cancerous tissue. If the pregnancy is completed, other hormones cause the breast tissue to differentiate into milk-producing tissue. If pregnancy isn't completed, the excess estrogen leaves the tissue free to grow into abnormal or even cancerous cells.]

  4. But "pregnancies which abort spontaneously (miscarry) usually generate subnormal amounts of estradiol; no increased risk of breast cancer is seen.

  5. The incidence of breast cancer is dramatically increased in rats whose pregnancies are aborted."
Most newsworthy in this regard, as I stated in Kingston, was the fact that in the editors' response to our letter in the JNCI not one of these biological facts was challenged!

Then there was the intriguing news about the mysterious appearance of the ABC link in Australian women. This evidence had been suppressed for seven years.

Back in 1988, a study on dietary risk factors for breast cancer in Australian women was published in the American Journal of Epidemiology. However, the study, principally authored by Dr. T.E. Rohan (now in Toronto with the National Cancer Institute of Canada), also listed standard risk factors -- including reproductive history and family history. None of these factors had a statistically significant impact on Australian women in the study (except for removal of the ovaries). Abortion was never mentioned in the 1988 paper.

It was a 1995 paper, principally authored by a French researcher Nadine Andrieu, where the Rohan data on abortion made its first appearance. And it showed a statistically significant 160% breast cancer risk increase among women who had chosen abortion -- much stronger even than family history in these Australian women.

Why were the abortion data suppressed for seven years? Dr Rohan acknowledged, in a phone call I placed to him, that with the politically sensitive status of abortion, he had never even tried to include the results on abortion -- the strongest connection he found -- in the original 1988 paper.

"Canada's national newspaper", the Globe and Mail (July 15) called my presentation "one of the most controversial" of the Kingston conference. Indeed, it provoked many questions from the audience, the first from Ms. Abzug herself.

She wanted to know, if induced abortion increases breast cancer risk, how could Japan, which has had a high abortion rate for decades, have the world's lowest breast cancer rate? The answer which was explained in detail to the Kingston audience (as well as NRL News readers [4/6/95]) is simple.

Four epidemiological studies on Japanese women have been published since 1957. All show increased risk, with an average risk increase of about 100%. All these studies were scientifically correct: they compared Japanese women who had undergone an abortion to Japanese women who had not -- not to women from the U.S. or anywhere else. And in Japan, where breast cancer risk in the absence of abortion is about 2%, abortion doubles it to about 4% -- still much lower than the U.S. breast cancer rate.

Other provocative questions followed from this audience, well represented by breast cancer survivors, most notably concerning survival among women diagnosed with breast cancer while pregnant, and those who got pregnant after treatment for breast cancer. I reported that, contrary to commonly given medical advice, survival was markedly better in both cases among women who chose childbirth instead of abortion. Ironically, the best research in the world on these subgroups of women was performed at the Princess Margaret Hospital in Toronto, only 150 miles from where we sat in Kingston.

As the Globe and Mail article also reported, my world conference presentation "received applause from the audience, which included many pro-choice advocates." Thankfully, some organization concerned with women's health and women's rights has finally taken a good look at the ABC link. After all, abortion is the single most avoidable risk factor for breast cancer, and women everywhere have the right to know that!


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Posted 9 Sep 2000.

Copyright 1997 by Joel Brind and National Right to Life News
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