The Abortion and Breast Cancer Connection

Breast Cancer and Abortion: Is There a Link?

Germain Kopaczynski

Ethics and Medics May 1995
Volume 20 Number 5

The statistics are cause for grave concern: according to the American Cancer Society, there are 182,000 cases of breast cancer diagnosed each year and 46,000 woman die annually of the disease. Why has there been such a high rate in the incidence of this type of cancer? And why especially in the United States? Since the cancer rates are higher among well-educated than among poor women, some have opined that the reason for this may well be lifestyle factors such as diet. Other studies seize upon another possibility; reproductive decisions.

Recent Studies
The catalyst for the spate of recent interest in the number one killer of American women was a recent study. "Risk of Breast Cancer among Young Women: Relationship to Induced Abortion" written by Janet Daling and appearing in the Journal of the National Cancer Institute 86 (1994), 1584-1592. While Daling's article may be the most recent, it is certainly not the first to study this purported link. In the medical literature, we find that as far back as 1957, researchers in Japan were discussing the increased risk from breast cancer following both spontaneous and induced abortions. Anyone who consults MEDLINE, an online bibliography, will see a steady stream of recent articles in medical journals ever since, including that of H.L. Howe et al., "Early Abortion and Breast Cancer Risk Among Women Under 40," International Journal of Epidemiology 18 (1989), 300-304.

Before Daling's 1994 article, perhaps the most famous and oft-cited was that of M.C. Pike et al., "Oral Contraceptives Use and Early Abortion as Risk for Breast Cancer in Young Women," British Journal of Cancer 43(1981), 72-76, which concluded that a first-trimester abortion before a woman has had her first full-term pregnancy was associated with a 2.4-fold increase in breast-cancer risk. What is important to note here is that the first pregnancy when taken to full-term affords a woman an appreciable measure of protection against breast cancer; an induced abortion of a first pregnancy places a woman at a much greater risk for the dread disease.

Studies on the link between the rise of breast cancer and the incidence of abortion have been so numerous and so persistent that in January of 1994, the Washington-based National Women's Health Network [NWHN] felt obliged enough to come out with an opposing fact sheet entitled "Abortion and Breast Cancer: The Unproven Link." However, the accumulating evidence supports the opposite assertion, viz., that there well may be a link, as we shall see.

How Abortion May Generate Breast Cancer
One of the most intriguing of the studies linking breast cancer and abortion is that by J. Russo and Carcinogenesis: Pregnancy Interruption as a Risk Factor," American Journal of Pathology 100 (1980), 497-512. Using rats in an experiment, the authors attempt to explain how the link between abortion and breast cancer comes about in a physiological sense.

The NWHN document referred to earlier is not unaware of the Russo study and what it may mean:

Biological evidence from animal studies demonstrates that there is a plausible explanation for an association between breast cancer and abortion. When a pregnancy is interrupted, as in abortion, the mammary glands contain some areas with completely differentiated structures and other areas of immature cells. (Russo, 1981). Thus the breast is more susceptible to the initiation or promotion of cancer. Studies to this effect in rats are useful since rats' breast tissue is similar to humans.

How does this link come about? Researchers are turning their gaze to the issue of cell growth to find an answer. In a recent article appearing in the Journal of the National Cancer Institute 85, no. 24 (December 15, 1993) "Does Abortion Increase Breast Cancer Risk?" Troy Parkins mentions the Daling study (which had not yet been published) as tending to the conclusion that there is a 50% to 90% increase in breast cancer risk for women who have had an abortion before the age of eighteen, and tries to explain the findings by putting forward a hypothesis by Leon Bradlow, M.D., Director of the Laboratory of Biochemical Endocrinology at the Strang-Cornell Cancer Research Laboratory in New York who said, in effect, that a full-term pregnancy confers a protective benefit upon women, helping them avoid breast cancer. Parkins paraphrases Bradlow's argumentation:

Numerous scientists believe the protective benefits of pregnancy arise from having differentiated breast cells because breast cancer arises in undifferentiated cells. During the first half of pregnancy, increased concentrations of estrogen stimulate the mother's breasts to grow. During the second half of pregnancy, breast cells differentiate to allow milk production. There is substantial scientific evidence that estrogen increases breast cancer risk. If a pregnancy is cut short by spontaneous or induced abortion, the woman experiences high estrogen concentrations without differentiation. Some doctors say this explains studies that show an increase in breast cancer risk among woman who have had a spontaneous or induced abortion. Bradlow feels strongly that these studies should be publicized.

Ideology Meets Science
What makes this issue so volatile, of course, is the abortion connection. The NWHN fact sheet, while aware of the pertinent scientific studies attempting to establish the link between breast cancer and abortion, especially of a first pregnancy before the age of eighteen, concludes: "There is currently no scientifically acceptable reason for women to factor an increased risk of breast cancer into their decision whether or not to continue a pregnancy." I find this statement odd because the very studies cited by NWHN lead to the opposite conclusion. What is going on here? Why such an incongruity when dealing with an issue of life and death for so many women? While conceding that women should have as much information as possible about all the factors which may contribute to breast cancer risk, the last paragraph of the NWHN may give the explanation: the group "supports all reproductive rights, including the right to abortion." Is this concern for women's health or is this feminist ideology at work?

Researchers like Daling, while they may be personally pro-choice, believe that this information should become part of the total package of women's right to know everything pertinent about their bodies and the possible harmful effects of the abortion procedure (See Daling's remarks in "Do Abortions Raise the Risk of Breast Cancer," Time Nov. 7, 1994, p.61).

The Sacred Cow Meets the Smoking Gun?
The NWHN may well be right in saying that the link between breast cancer and abortion of a first pregnancy has as yet not been established without any trace of scientific doubt. No researcher, as far as I can tell, is saying that abortion is the only factor responsible for the rapid rise in breast cancer rates among American women. It is one factor, nothing more, nothing less. When the NWHN and other groups take the ideological approach that they do, is it my imagination or are they, in fact, emulating the tactic employed by tobacco companies discounting the purported link between lung cancer and smoking? If abortion is not the smoking gun, neither should it be regarded as a sacred cow.

Feminist Adrienne Rich once wrote: "Abortion is violence: a deep desperate violence inflicted by a woman upon, first of all, herself" (Of Woman Born: Motherhood as Experience and Institution {New York: Bantam Books, 1977}, pp. 268-269). In the tortured prose of this passage, and in the light of the medical studies on the topic we have consulted, Rich may be saying much more than she knows.

Germain Kopaczynski, O.F.M. Conv.
Director of Education
Pope John Center


The Abortion-Breast Cancer Link

Angela Lanfranchi

Ethics and Medics January 2003
Volume 28 Number 1

Thirty years ago when Roe v. Wade was decided, I was a third-year medical student at Georgetown University. The third year is when medical students leave the classroom and go into hospitals to do their clinical rotations. The ruling had an immediate effect on the practice and ethics of medicine. No longer would my obstetrics professor tell his students that his was a unique specialty, that he always had two patients to consider, mother and child. Now only when the mother wanted the child did we treat two patients. When the mother didn't want the child, no consideration would be given to the unborn's humanity. It was no longer a child but a blob of tissue, a "product of conception," a parasitic entity or whatever the mother chose to call "it." For the first time, every doctor in every state could legally kill another human being. On my pediatric rotation that year, I helped to resuscitate a child who was born four months prematurely crying aloud, struggling to breathe. She was the result of a failed abortion. She was wizened and burned from the hypertonic saline used to try to kill her on the hospital floor just below the nursery. I can still see her clearly in my mind's eye.

One and a half years after Roe v. Wade, when I graduated something else very profound had happened. The Hippocratic Oath we took, that had stood medicine in good stead for twenty-four hundred years, had been changed. The part about refusing to give a woman a pessary to induce an abortion had been deleted.

Ten years after Roe v. Wade I watched my mother fight and lose her battle with breast cancer. Added to her physical torment was her mental anguish at the thought of leaving my youngest brother before he was fully grown.

Twenty years after Roe v. Wade, I was settled into a surgical practice devoted to breast cancer. I found that breast cancer risk was no longer one out of twelve women, as I had learned in medical school, but had increased dramatically to one out of eight. Not only that, but the women with breast cancer were no longer postmenopausal grandmothers, but young thirty-year-old mothers with toddlers. I knew from my own painful experience what they would face.

The Roe v. Wade ruling not only changed the Oath I took at graduation, but also my practice. We all know someone, either personally or through friends and family, who has had breast cancer. Breast cancer is the only major cancer that continues to rise. Most of this increase has occurred in members of my own generation, those women who were twenty-five to thirty-nine when Roe v. Wade was decided.

Epidemiological Evidence
Abortion is a risk factor for breast cancer. I see it every day in my practice. Thirty percent of my breast cancer patients who are in their thirties do not have a family history of cancer, but have had an abortion. It is estimated that an additional ten thousand cases of breast cancer occur each year because of abortion.

The abortion-breast cancer link (ABC link) is supported by the published epidemiological studies, the physiology of the breast, and the experimental studies done in mammals. Epidemiological studies overwhelmingly support the ABC link; however, to put them into proper perspective, one must understand why some have referred to epidemiology as a "pseudo-science."

Epidemiology can be defined as the study of disease in large populations. These studies can never be taken as proof positive that any risk found is causal. For example, large studies would probably show unequivocally that more people with lung cancer carry matches in their pockets than those without cancer. This would not mean that matches cause lung cancer, even though large studies were done well, were statistically significant, and were reproducible. Biology has shown that it is the carcinogens in match-lit cigarette smoke which causes lung cancer. Similarly, without the support of the well-known breast physiology and experimental data, the studies documenting an abortion-breast cancer link would be inconclusive.

Let us look at the epidemiology first, and then the supporting data. Epidemiologists have defined five criteria which should be largely satisfied before a risk factor can be considered a potential causal risk.

1. The patient must be exposed to the risk before the cancer develops.

2. There must be similar findings in many studies. One or two studies can never be taken to prove anything. In the case of the ABC link, twenty-eight out of thirty-five worldwide studies show a link between abortion and breast cancer. Thirteen out of fifteen studies done in the U.S. show a link.

3. There must be statistically significant increases. Scientists need to show with ninety-five percent certainty that their results could have not occurred by chance alone. There are seventeen statistically significant studies that show a link between abortion and breast cancer and eight were done in the U.S.

4. There should be a dose effect, that is, the risk should be higher with more exposure. In the case of cigarettes and lung cancer, the more cigarettes one smokes, the greater the risk of lung cancer. In the case of abortion, the longer one is pregnant before the abortion, the higher the risk of breast cancer. This was shown in the 1994 Daling study commissioned by the National Cancer Institute.(1)

5. There should be a large effect observed. In the case of abortion and breast cancer there are subsets of women with very high risk. For example, in the 1994 Daling study, all the teenagers who had abortions at eighteen or younger and had a family history of breast cancer developed breast cancer by the age of forty-five. The risk could not be calculated and was reported as infinity.

Now even having satisfied these criteria, the ABC link would still not be proven unless there was a sound biological basis for this risk. All the studies in the world showing that lung cancer occurs most frequently in people who carry matches in their pockets does not mean matches cause lung cancer. I believe that the biological basis for the ABC link is the most powerful and persuasive argument supporting it.

The Biological Basis
The same biology that accounts for ninety percent of all risk factors for breast cancer accounts for the ABC link. Simply stated, the biology rests on two principles.

1. The more estrogen a woman is exposed to in her lifetime, the higher her risk for breast cancer.

2. The younger a woman's breasts mature from Type 1 and 2 lobules to Type 3 and 4 lobules, the lower her risk.

If a woman starts her menstrual cycles early, e.g., at age nine, and continues to menstruate into her late fifties, she is at higher risk because she has more years exposed to monthly estrogen elevations. Through a large, recent, well-publicized study, women became aware that the estrogen in their hormone replacement therapy increased their breast cancer risk. In a similar way, birth control pills elevate breast cancer risk.

Type 1 and 2 lobules are known to be where cancers arise. Type 3 and 4 lobules are mature and resistant to carcinogens. When a child is born, she has only a small number of primitive Type 1 lobules. At puberty when estrogen levels rise they form Type 2 lobules. But it is only through the hormonal environment and length of a full-term forty-week pregnancy that there is full maturation to Type 3 and 4 lobules. This maturation protects a woman and lowers her risk of breast cancer. This is why women who undergo a full term pregnancy have a lower risk of breast cancer and why women who remain childless have a higher risk of breast cancer. It is the interplay of these two principles, estrogen exposure and breast lobule maturation, that accounts for the fact that abortion can cause breast cancer. Within a few days of conception, a woman's estrogen level rises. By the end of the first trimester estrogen levels have increased by two thousand percent. Every woman notices her breasts get sore and tender because the estrogen stimulation results in the multiplication of Type 1 and 2 lobules. It is only after thirty-two weeks that her breasts stop getting larger and mature into Type 3 and 4 lobules in preparation for the breast feeding of her child.

If abortion ends her pregnancy before full maturation of her breasts, she is left with an increased number of the immature Type 1 and 2 lobules. She now has a greater number of breast lobules where a cancer can arise. This causes her to be at greater risk for breast cancer. It is through this same biologic mechanism that any premature birth before thirty-two weeks more than doubles breast cancer risk.
Suppression of Data?
The question now arises, if it is true that abortion increases breast cancer risk, why would organized medicine not support the data? One reason is fear of the results of peer pressure. In my own case, I have worried that I would lose referrals from ob-gyns who do abortions when I have lectured on this topic. Even a family doctor who would refer numerous patients said to me, "You don't tell my patients that, do you?" I worried about my practice. I was also worried about being labeled a pro-life zealot or an anti-choice fanatic. I can understand why a Harvard professor of risk assessment at a Boston cancer institute would tell me privately that she knew abortion was a risk factor for cancer but would not bring it up in her talks on risk. She might lose her job. I have a colleague who did lose an appointment at a New York medical school just because he was quoted in The Lancet giving credence to a study supporting the ABC link.

Janet Daling, an adamantly pro-choice epidemiologist, told me she refused to speak on the topic anymore because she was tired of having rocks thrown at her. I learned what it felt like first-hand when I presented a research project in a poster session at the San Antonio Breast Symposium in December 2001. Although the abstract had been accepted six months earlier and had the word "abortion" in the title, the program director angrily accused me of using his meeting as a platform to hand out anti-abortion literature. Most troubling is that several years ago the then-president of the American Society of Breast Surgeons told me that her board did not want to have a speaker on the subject at their meeting because they felt it was "too political." I argued that it was also medical, but to no avail. The director of the Miami Breast Cancer Conference also felt it was "too political." He returned a check I had given him so that our Breast Cancer Prevention Institute could not even have an exhibit table. I am waiting for a response from the American College of Surgeons. I hope they too will not deem this topic "too political." What is so telling is that not one authority in the field of breast cancer that I have spoken to directly has said that the data is not true or that I was wrong about the science.
Perhaps another reason physicians have not acknowledged the link is the Semmelweiss Phenomenon. In 1840, forty years before the germ theory was known, a resident in obstetrics noted that there was a twenty-five percent mortality rate from childbed fever on the doctors' ward. On the midwives' floor, where there was frequent hand washing, the mortality rate was only two percent. When at his suggestion an experiment was done by having doctors wash their hands, the infection and death rate on their own ward was greatly reduced. Instead of rewarding Semmelweis and promoting hand washing to reduce mortality, he lost his job and was vilified. It seems that it was easier for doctors to let women die than change their own practices. They would have to acknowledge that the midwives had provided better care and that professors had been corrected by a lowly resident.

Women's groups such as the National Organization for Women have not brought this information out. The idea of safe and legal abortion is the foundation of their cherished reproductive rights. What if it became known that abortion is not safe but lethal to some women exercising that right? The abortion industry does not want to lose clients for its billion-dollar industry, so their trade organization, the National Abortion Federation, tries to dismiss it.

Signs of Hope
Public knowledge of abortion as a risk factor for breast cancer will not only help women obtain true informed consent; it also helps women who have had an abortion. Once a woman knows she is at higher risk, she will be more likely to get screened with mammograms. This can increase likelihood of survival should she develop cancer.

Even if someone remains unconvinced of the causal nature of the abortion-breast cancer link, surely no one can feel that there is so little evidence that women should not be informed of the possibility. It is unconscionable that women's lives and health are sacrificed to maintain an attitude of political correctness.

I am glad to report there are signs of hope. This past June the National Cancer Institute took down its inaccurate and misleading fact sheet on the ABC link on its website. Twenty-eight U. S. Congressmen had sent a letter to the NCI's director pointing out the errors. My older textbooks did not even mention abortion as a possible risk. The newer ones do, even if they try to dismiss the data as inconclusive. One very notable exception to this was written by a researcher who is at Georgetown University, Professor Robert Dickson, who first included it in his chapter on the molecular biology of breast cancer more than ten years ago.(2)

The issue is being discussed in the press. Crisis magazine, a Washington, D.C.-based publication, recently explored this issue in a feature article. There have been countless letters to the editor in newspapers all over the country by laymen and doctors. Miss Oregon, Brita Stream, had as her platform the abortion-breast cancer link and went on to the Miss America pageant in Atlantic City this year. This issue has also entered breast cancer research politics. The Coalition on Abortion/Breast Cancer, an international lay organization, has made the public aware of the issue. They have made women aware that the Susan G. Komen Foundation, an organization which raises money for breast cancer research, also gives this money to Planned Parenthood. They pointed out to Komen and its donors that Planned Parenthood caused a significant amount of breast cancer as the nation's largest abortion provider. This has placed pressure on the Komen organization to stop that practice, with some success.

A month ago I saw in my office identical-twin women. One had several abortions as a teenager and was thirty-six years old when she got breast cancer. I was able to reassure her worried sister, who had a child in her twenties, that she did not share the same risks as her twin and that most likely her biopsy would be benign. When the results came back, it was. An analysis of my own patients with breast cancer in their thirties showed thirty percent had abortions but no family history of the disease.

The most important paper concerning the abortion-breast cancer link was the 1996 meta-analysis done by Dr. Joel Brind.(3) His paper prevented someone from saying, "Some studies say yes, some studies say no." See the chart on the following page showing his meta-analysis. All results on the right of the vertical line are the ones that show a link. At the time of publication there were seventeen out of a total of twenty-three. If it had not been published, I would still be in my office wondering why I have so many thirty-year-olds with breast cancer.

When Dr. Brind's study appeared it created a furor. In response, Dr. Stuart Donnan wrote an editorial in which he said, "I believe that if you take a view (as I do), which is often called `pro-choice,' you need at the same time to have a view which might be called `pro-information' without excessive paternalistic censorship (or interpretation) of the data."(4) Dr. Brind likes to add "And that's from an understated Englishman." At the risk of political incorrectness, I would like to add, "God bless them both."

Angela Lanfranchi, M.D., F.A.C.S.
Breast Cancer Prevention Institute
Poughkeepsie, New York