The Abortion-Breast Cancer Link: Those Stubborn Facts Again (Part One of Four)


By Joel Brind, Ph.D.

The following article originally appeared at NRL News Today. See the end of this article for links to the rest of the series.

In this first of four articles on the abortion-breast cancer (ABC) link, Dr. Joel Brind, a professor of biology and endocrinology at Baruch College of the City University of New York, chronicles the history of epidemiological data going back over 50 years that shows a consistent statistical connection between a history of induced abortion and a higher incidence of breast cancer among women all over the world. He will also briefly talk about the curious logic used by deniers of the ABC link.

Joel Brind, Ph.D.

By way of background, abortion raises a woman’s risk for breast cancer in two ways; the debate is over the second, not the first. Scientists have long understood that the risk of breast cancer is reduced when a woman completes a full-term pregnancy. This “protective effect of childbearing” is lost with an abortion. The second way abortion increases the likelihood of breast cancer is that an abortion leaves a woman with more cancer-vulnerable breast tissue than she had before she became pregnant.

In 1957, a nationwide study in Japan published in the Japanese Journal of Cancer Research found that women who had breast cancer reported having had three times as many pregnancies end with an induced abortion. Of course, there were few studies in those days, as induced abortion was neither legal nor common in most of the world — and breast cancer was not that common either!

Most studies, in fact, did not distinguish between induced abortion and spontaneous abortion (what we usually refer to as miscarriage), a natural event that generally does not increase the risk of breast cancer. I will talk about the importance of this distinction in Parts Two and Three.

Then there were the results of a very prominent series of World Health Organization-sponsored studies in the late 1960′s. Led by a Harvard research team, the WHO study looked at women from four continents to find out whether early pregnancy reduces breast cancer risk. That turned out to be true for full-term pregnancies. But they also found that the results “were in the direction which suggested increased risk associated with abortion — contrary to the reduction in risk associated with full-term births.”

The famous 1970 paper that summarized these WHO findings firmly established that full-term pregnancies confer protection against breast cancer. It has been unequivocal for over 40 years that a pregnant woman who chooses abortion will end up with a higher long-term risk of breast cancer than if she chooses instead to let nature take its course.

Every reasonable standard of informed consent requires a doctor to warn a patient of any adverse health consequences of having the intervention in question — abortion in this case  — compared to not having the intervention. That alone defines a duty for abortion practitioners to inform their patients of the increase in future breast cancer risk.

But the ensuing four decades of research around the world, a world with an ever increasing number of women having had an induced abortion, have shown that it is even worse: Women who choose abortion are more likely to get breast cancer than if they had not gotten pregnant in the first place.

This trend, known among epidemiologists as the “independent risk” of abortion, has been the center of the controversy raging in the public square. Evidence of this independent risk of abortion first showed up among American women in a prominent study from USC published in 1981 in the British Journal of Cancer. Another dozen American studies showed the independent effect during the 1980′s and 90′s, as well as another dozen studies from Europe and Asia.

In 1996, along with colleagues from the Penn State Medical College, I published, in the British Medical Association’s epidemiology journal, a meta-analysis of all 23 studies then extant. Our paper proved that the average 30 percent increase in breast cancer risk among women who have had an induced abortion was “statistically significant”: in other words, this increase was more than 95 percent certain not to be due to chance. In the last five years, studies continue to emerge from nations where both abortion and breast cancer used to be rare – China, Iran, Turkey, Armenia — showing a clear and significant independent ABC link.

Yet strangely —  and tragically — to all the world’s most prominent purveyors of public health information, from the U.S. National Cancer Institute, American Medical Association and the cancer charities such as the American Cancer Society and the Komen Foundation, to Health Ministries around the world and the WHO itself, the ABC link does not exist!

And the argument upon which all the denials are based boils down to something called variously, “reporting bias” or “response bias.” It goes like this:

When a study population of women is interviewed to determine their reproductive history, the argument is that healthy women will be more reluctant to admit they had an abortion, whereas women with cancer are more likely to tell the truth about their abortion history.

If this is true, then studies which rely on interviews that look back in time (retrospective studies) will overestimate the association of induced abortion with breast cancer patients, compared to healthy women. Proponents of this hypothesis go on to claim that only a study based on medical records, or one which follows women prospectively in time – i.e., a study in which the abortions are recorded before anybody knows who will get breast cancer – can give accurate results.

As much of a stretch as the response bias hypothesis seems – flying in the face of a half-century’s worth of data from studies on women from all over the world conducted by long-standardized epidemiological methods – it is a testable hypothesis. In fact it has been tested again and again, and found wanting, but that has not muted the chorus of official denial of the ABC link.

That leads to part II of this series, in which we will segue from the ABC link as the focus of our inquiry, to the world-wide cover-up of the ABC link, and its now over 40-year-long trail of published evidence.


Joel Brind, Ph.D. is a professor of biology and endocrinology at Baruch College of the City University of New York and co-founder of the Breast Cancer Prevention Institute.  He is a frequent contributor to NRL News and NRL News Today.

This article is reprinted with permission from NRL News Today.

Learn More:
The Abortion-Breast Cancer Link, Part I: Those Stubborn Facts Again
The Abortion Breast Cancer Link, Part II: The Cover Up
The Abortion-Breast Cancer Link, Part III: The Dagger Under the Table
The Abortion-Breast Cancer Link, Part IV: The Biology

For the most complete online library of published studies on the physical and psychological effects of abortion, visit


The Abortion-Breast Cancer Link: Those Stubborn Facts Again (Part One of Four) — 2 Comments

  1. First, Thanks you from the bottom of my heart for the work that you do! I want to get the word out here in the Harrisburg, Pa. area about the links that cause breast cancer. Every October thousands and thousands of people flock to Harrisburg “Find the Cure” for Breast cancer.

    There are booths of all kinds and people walk around handing out pamphlets and papers all pink with Purple ribbons. So I thought we could put together a couple of short stories or links to organizations like yours. I have a very pro-life printer who will print the papers om pink paper with the appropriate purple ribbons. We plan to print them in English and Spanish. We would like to use both sides of the paper. We can convert to Spanish.

    I want to use statistics on birth control (Class1 carcinogens) and abortions.

    Now what I’m asking may not be possible on one side of a sheet of paper. So if it took 2 or 3 pages so be it.

    I truly believe we can change the climate in our area if we can get the truth out. I can just imagine women finding out that they have been lied to all these years. A woman scorned is a powerful thing.

    May God continue to bless you and you fellow workers in the vineyard.

    Bob O’Neill
    Mechanicsburg, Pa.

    I’m going to print all 4 articles and make them a part of our next P/L Meeting
    I’m already on you mailing list…….

  2. Dear Bob O’Neill.
    I think your idea about educating the public is great. I also want to thank Dr. Brind for all his work over so many years. I have tried to disseminate this information but find that otherwise reasonable and amiable people, distrust scientific information because it is “coming from biased right wing sources”. I have actually written to legislators in NC, asking them to have a hearing about the suppression of pro-life information in the schools as well as the media. I wonder why we’ve never made a big noise about that? The Live Action protest, outside ABC recently. is the only such event that I recall. If we were allowed into the schools with laws that also protect us from defamation, we could reach young women before they ever show up at the abortion clinic or seek contraception. We need that protection because pro-choice ideology predominates. Two generations have been brainwashed.

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