Because this material is so valuable and because links to Web sites can become invalid over time, this material is copied, February 14, 2011, rather than just linked from
A. Neal de Gaston

Coalition on Abortion/Breast Cancer

It cannot be said that all women who have breast cancer have had abortions.  Similarly, not all women who have had abortions will get breast cancer.  Nevertheless, abortion is the most preventable risk factor for breast cancer.

Two Ways that Abortion Raises Breast Cancer Risk

Women have the right to know that two breast cancer risks are associated with abortion - a recognized risk and a debated risk.


All experts agree that the longer a woman waits to have her first full term pregnancy, the greater her breast cancer risk is. Delaying the birth of a first child significantly increases risk because the childless woman has immature, cancer-vulnerable breast tissue - Type 1 and 2 lobules where 95% of all breast cancers are known to develop. Her breast tissue does not mature into cancer-resistant tissue until the last months of a full term pregnancy. By the end of a 40-week pregnancy, 85% of her breast lobules are mature, cancer-resistant lobules known as Type 4 lobules.

A delayed first full term pregnancy increases her risk because it extends the length of time during which her breasts remain susceptible to carcinogens. Scientists define an early first full term pregnancy as one that takes place before age 24.

Although delaying the birth of a first child is a known cancer risk, few experts have the intellectual honesty or the political courage to admit that abortion contributes to the breast cancer epidemic by causing a countless number of women to delay their first full term pregnancies every year.


Experts debate whether an abortion further increases risk by leaving the woman with more cancer-vulnerable breast tissue than she had before she became pregnant. This effect is known as the "independent link."

The breasts grow considerably during pregnancy while under the influence of high levels of the hormone estrogen, a known carcinogen. Estrogen causes the woman's normal and cancer-vulnerable breast lobules to multiply. If she has an abortion, she's left with more places for cancers to start in her breasts. If she has a baby, then other pregnancy hormones mature her breast lobules into cancer-resistant lobules during the last months of pregnancy. She's left with more cancer-resistant tisue than she had before she became pregnant.

Seventy-two epidemiological studies have been conducted since 1957; and 80% of these studies have shown that abortion increases the risk of breast cancer independently of the effect of delaying the birth of a first child. These epidemiological studies establish a correlation between abortion and increased breast cancer risk. Most of the recent epidemiological studies focus exclusively on the effect of the independent link, not the known risk of delaying the birth of a first child.

An independent link is also supported by:

1) Animal research [Russo & Russo Am J Pathology 1980];

2) The World Health Organization's acknowledgement that oral contraceptives and hormone replacement therapy containing estrogen and progestin are "Group 1 carcinogens." (Press Release #167, July 29, 2005);

3) The established risk showing that a premature birth before 32 weeks gestation more than doubles breast cancer risk. The hormonal changes to the breasts are the same whether the woman has an abortion or a premature birth before 32 weeks gestation. [Melbye et al. Br J Cancer 1999; Hsieh et al. Lancet 1999; Vatten et al. Br J Cancer 2002; Innes and Byers Int J Cancer 2004]

4) Plausible biological reasons why an abortion leaves a woman more susceptible to breast cancer.

Abortion is an "elective surgical procedure and a woman’s exposure to the hormones of early pregnancy -- if it is interrupted -- is so great, that just one interrupted pregnancy is enough to make a significant difference in her risk" [Professor Joel Brind, President, Breast Cancer Prevention Institute, Endeavour Forum Public Meeting, August 24, 1999, Malvern, Victoria, Australia].

Because American Women already face a high lifetime risk of developing breast cancer of about 12.5 percent, boosting that risk by even a small percentage through the procurement of a single induced abortion is comparable to the risk of lung cancer from long-term heavy smoking.  Approximately 1 in 100 women procuring an abortion is expected to die as a result of abortion-induced breast cancer.

A Medical Text and Henderson Lecture Acknowledge ABC Link

An Authoritative Medical Text for doctors who specialize in breast diseases discusses the causes of breast cancer.  It states that the exposure of the breasts to estrogen for long periods of time proportionately increases breast cancer risk, and it specifically identifies abortion as a risk factor.  It says, "Long-term exposure to endogenous estrogens (early menarche; late menopause; late age at first full-term pregnancy; and being overweight, leading to increased aromatization of circulating androgens to estrogens) appears to increase cancer risk.  Risk is decreased only with early menopause (natural or artificial) and childbearing.  However, first-trimester abortion increases risk."  empasis added [Robert B. Dickson, Ph.D., Marc E. Lippman, MD, "Growth Regulation of Normal and Maglignant Breast Epithelium," The Breast: Comprehensice Management of Benign and Malignant Diseases, edited by Kirby I. Bland MD and Edward M. Copeland III, MD; (1998) W.B. Saunders Company; 2nd edition; Vol 1, p.519.]  

(Click here to see the Credentials for the authors and editors of the medical text.)

The Medical Text cited the Henderson lecture to support the statement that "first-trimester abortion increases risk."  Henderson said, "Recently, we found that a first-trimester abortion, whether spontaneous or induced, before the first full-term pregnancy is actually associated with an increase in the risk of breast cancer."  [Henderson, B.E., Ross R., Berstein, L.; "Estrogens as a cause of human cancer," The Richard and Hinda Rosenthal Foundation Award Lecture, University of Southern California School of Medicine, Los Angeles, California: Cancer Res 48:246-253, 1988] 

The Henderson Lecture was published in 1988.  The statement asserting that abortion is linked with increased breast cancer risk was based on only two studies, the first of which Henderson co-authored and was the first published American study.  [Pike MC, Henderson BE, Casagrande JT, et al.  "Oral contraceptive use and early abortion as risk factors for breast cancer in young women, " Br. J. Cancer (1981) 43:72-76; and Hadjimichael OC, Boyle CA, and Meigs JW, "Abortion before first live birth and risk of breast cancer," Br. J. Cancer (1986) 53:281-284.]

A discussion of the Pike Study was provided by Dr. Joel Brind during his 1999 lecture in Malvern, Victoria in Australia.

National Institutes of Health and Centers for Disease Control

Scientists from the National Institutes of Health and the Centers for Disease Control, Bruce Stadel and Phyllis Wingo, and two other prominent epidemiologists were convinced of a link in 1986.  They co-authored a letter to the British journal, Lancet, and said, "Induced abortion before first term pregnancy increases the risk of breast cancer."  [Feb, 22, 1986, p. 436]  They acknowledged the independent effect of an induced abortion on breast cancer risk at a time when there were only two American studies linking abortion with the disease.  [Pike et al. (1981) Br J Cancer 43:72-6; and Brinton et al. (1983) Br J Cancer 47:757-62]

Why aren't women being told?

National Cancer Institute

Dr. Janet Daling, an abortion supporter, and her colleagues at the Fred Hutchinson Cancer Research Center were commissioned by the National Cancer Institute to conduct a study to determine if induced abortion raises breast cancer risk.  The study found that, "among women who had been pregnant at least once, the risk of breast cancer in those who had experienced an induced abortion was 50% higher than among other women."

High Risk Groups

Daling identified 3 high risk groups and reported these findings:

1) Women under the age of 18 or over the age of 29 who obtained induced abortions have more than a twofold increase in risk.

2) Women with a family history of breast cancer who procured an abortion were found to have statistically significant risk increases of 80 percent.

3) Teenagers with a family history of the disease who procured abortions before the age of 18 were found to have incalculably high risk.  All 12 women in Daling's study with this background were diagnosed with breast cancer by the age of 45.  [Daling et al. (1994) J Natl Cancer Inst 86:505-14.]

An additional high risk group was identified by Dr. Amelia Laing of Howard University:

1. African American women had a 50% increased risk before the age of 40, a 180% increased risk between the ages 41 and 49 and a 370% increased risk after age 50 if they'd ever procured at least one abortion. [Laing et al. (1993) J Natl Med Assoc 85:931-9] 

A subsequent study by this author comparing sisters, one of which had procured an abortion, reported a 144% increased risk. [Laing et al. (1994) Genet Epidemiology 11: A300]

Jane Orient, MD, a spokeswoman for the American Association of Physicians and Surgeons, told World Net Daily that, “If you look at the number of studies that show a connection, they vastly outnumber the ones that don’t, and the ones that don’t have been criticized for serious methodological flaws.” She reported that the elevated risk is “substantial, particularly in women who abort their first pregnancy at a young age and who have a family history of breast cancer. It’s something like 800 percent.” She added, “I think (doctors) should inform patients about this,” and the information “should include the potential connection with breast cancer as well as the long-term psychological risk.[John Dougherty, “Can doctors be sued over abortion? Those who don’t inform patients of breast cancer link could be targets,” World Net Daily, <>, March 27, 2002]

American Cancer Society

The American Cancer Society has stated in its fact sheet that abortion "may be associated with increased breast cancer risk."  [American Cancer Society, Cancer Facts & Figures -- 1996, at 12 (1996)]  (An employee of the American Cancer Society with the Office of Corporation Counsel has asked us to remove the Society's 1996 statement from our web site.  We have contacted the Society and asked them to inform us of the legal basis for their request, if any.)

Second Way Abortion Causes Breast Cancer

There is another way in which abortion increases the risk of breast cancer. Medical experts universally agree that it is healthier for a married woman not to postpone her first full-term pregnancy. [MacMahon et al. (1970) Bull Wld Health Org 43:209-21]

One Harvard study reported that each year that a woman postpones her first full-term pregnancy increases her breast cancer risk by 3.5%. [Trichopolous D, Hsieh Cc, MacMahon B, Lin T, et al. Age at Any Birth and Breast Cancer Risk. International J Cancer (1983) 31:701-704]

An abortion causes a woman to forego the benefit of increased protection from breast cancer which she would have obtained from an earlier first full-term pregnancy.  World Health Organization scientists in 1970 confirmed this saying that, "It is estimated that women having their first child when aged under 18 years have only about one-third the breast cancer risk of those whose first birth is delayed until the age of 35 years or more."  In addition, this protective effect was not observed among women who'd had an incomplete first pregnancy.  [MacMahon B, et al.  Bull Wld Health Org. 1970; 43:209-21] 

(Note: Our group advocates abstinence before marriage, but once a woman is married, we do not recommend postponement of a first full-term pregnancy.  We believe women have a right to be fully informed about the adverse effects of delayed childbearing and induced abortion.)

The British journal, Lancet, published a large meta-analysis on the benefits of breastfeeding and childbearing in which data were collected from 47 epidemiological studies in 30 countries. It was found that the relative risk of breast cancer declined 4.3% for each 12 months of breastfeeding and 7.0% for every birth. It was concluded that the incidence of breast cancer in developed nations could be reduced by more than half if only women would bear more children and breastfeed for longer periods of time and that “the lack of or short lifetime duration of breastfeeding typical of women in developed countries makes a major contribution to the high incidence of breast cancer in these countries.” [Valerie Beral, (July 20, 2002) The Lancet, 360:187-95] 

A woman can’t breastfeed a child who’s been aborted.

Graham Colditz, MD, a Professor of Medicine at Harvard Medical School and a Professor of Epidemiology at the Harvard Medical School of Public Health, reported that one-half of the differences in the rates of breast cancer between the developed and undeveloped countries are attributable to childbearing patterns, including age at first birth, number of births and breast feeding.  He said, "Comparing the reproductive patterns with six or more pregnancies with the typical pattern of two pregnancies in the developed world, we have shown that at least 50% of the international variation in breast cancer rates can be explained by these patterns of childbearing."  [Graham Colditz, MD, "Relationship Between Estrogen Levels, Use of Hormone Replacement Therapy and Breast Cancer," JNCl (1998) 90:814-823.] 

It is known that women, who start their families earlier in their reproductive years, have larger families and breast feed for long periods of time, have a reduced risk of breast cancer.  It is not politically correct, however, to speak this truth to women.

If American breast cancer rates can be reduced by 50% through a cultural change in childbearing patterns, then it is incumbent on scientists to inform women of these facts and let us make the health decisions for ourselves.  The alternative is to continue the status quo at the expense of women's health.

Why aren't women being told?

Considering the high incidence of breast cancer among American women, why are married women being encouraged to postpone their first full-term pregnancies and to reduce the size of their families?  Why are abortifacients and abortions being foisted on women?

Breast cancer is the greatest cancer killer among American women between the ages of 20 and 59.  The incidence of cancer climbed 40% in the last quarter of the 20th Century (since Roe v. Wade legalized abortion in the United States in 1973), while the incidence for all other cancers has either remained the same or declined.  ["Breast Cancer Numbers Up, But US Cancer Deaths Drop," Reuters, June 5, 2001]

It is extraordinary that certain women's organizations, i.e. the National Organization for Women, champion what is euphemistically known as "reproductive rights," despite the fact that the medical community has long known that delayed first full-term pregnancy raises breast cancer risk.

Many corporations and wealthy individuals, including Bill Gates, the Rockefellers, Ted Turner and Warren Buffet, may be contributing to the rampant breast cancer rates in the United States and elsewhere in the world by donating to population control groups, including Planned Parenthood, the nation's largest abortion provider and a distributor abortifacients.  American taxpayers unknowingly contribute to the high incidence of this disease because their taxes subsidize Planned Parenthood and the United Nations Family Planning Agency (UNFPA).

It is especially appalling that even the Susan G. Komen Breast Cancer Foundation which sponsors the Race for the Cure in many locations around the country gives a portion of its funds to Planned Parenthood.  (See our July 18, 2001 press release regarding the Komen Foundation)  Surely Komen's medical experts would agree that the delay of a first full-term pregnancy results in increased risk of breast cancer.  No self-respecting medical expert would dare to disagree.

One of the difficulties with anti-cancer organizations is that radical feminists took up the breast cancer cause in the 1980's.  They saw this as a means of championing women's rights, so it must have come as a surprise to them when they learned that their dominant concern -- abortion -- caused breast cancer.  Once it became apparent that they had a conflict between abortion ideology and protecting women's health, abortion won hands down!

Updated 05/30/07.