Abortion and Breast Cancer:
THERE IS NO LINK

Scientific research does not support a link between abortion and an increased risk of breast cancer later in life, researchers at a National Cancer Institute concluded at the end of a special workshop on Feb. 26, 2003. Participants concluded that studies that claimed a connection between abortion and an increased risk of breast cancer were "flawed." Larger better-designed studies indicate NO link. more

Swedish Study

Since 1994, several exhaustive studies have found no tie between abortion and breast cancer. A 30-year Swedish study of 49,000 women indicated no link between abortion and breast cancer. Furthermore, the Swedish study did not suffer from an inaccurate reporting of medical histories because it was based on a national medical registry in Sweden and not based on interviews.

Largest Study Ever in Denmark, 1997

Published in 1997, a study from Denmark indicates no increased risk for women who had abortions when they analyzed medical histories of more than 1.5 million women. This larger more comprehensive study is persuasive because it does not rely upon interviews. Data came from Denmark's national health records, thereby eliminating the possibility of "recall bias." The study showed that even women who had two or more abortions were no more likely than those who never had an abortion to develop breast cancer.

The Danish study analyzed the abortion histories of 10,246 women with breast cancer among 1,529,512 women. A total of 370,715 abortions occurred in 280,965 women. Among the 2.3% of women who had abortions after the first trimester (after 12 weeks), the researchers found a gradually increasing risk of breast cancer as the stage of pregnancy advanced. However, researchers concluded that the actual number of women with second trimester abortions was too small to warrant a firm conclusion. In Denmark, abortions are both legal and free, so there are fewer reasons for women to have abortions after 18 weeks unless there are other medical problems. These other problems might themselves be the cause of the increased cancer rate.

Interestingly, women who had abortions prior to seven weeks of pregnancy actually showed a slightly decreased risk of developing breast cancer. But again, the actual number of women in this category is very small.

Also in January 1997, a Netherlands Cancer Institute study documented the existence of "recall bias" and concluded it was a significant factor affecting early studies on the link between abortion and breast cancer.

Other Published Reports: According to findings published in the January 2000 issue of Epidemiology, women who have had an induced abortion are at no more risk for breast cancer than their counterparts who did not have an abortion. Researchers at the University of Minnesota's School of Public Health-Division of Epidemiology and the Mayo Clinic examined a study sample of 1986-1995 data from 37,247 Iowa Women's Health Study participants ages 55-64, who, at the 1986 baseline, reported no history of breast cancer. Through 1995, 653 women underwent an induced abortion. The authors found that the age-adjusted relative risk of breast cancer among women with prior induced abortion was no greater than those who had never undergone an abortion, nor did the risk increase with increasing numbers of induced abortions. There were 438 cases of breast cancer per 100,000 person-years among women who reported they did have an abortion, compared to 392 cases of breast cancer per 100,000 person-years for women who did not have abortions. (Lazovich et al., Epidemiology, 1/00 issue). As reported by the Kaiser Daily Reproductive Health Report, Jan. 25, 2000.

Political Fallout

Anti-abortion groups are constantly searching for ways to frighten women away from choosing abortion. In fact, anti-abortion groups are the only ones actually telling women to avoid abortion as a means of protecting against breast cancer. They have even proposed legislation to require that women seeking abortion be informed of studies showing an increased risk for breast cancer. This legislation is particularly dangerous because it does nothing to help women understand the true causes of breast cancer, nor does it help an individual woman understand her own risk .

The National Cancer Institute and the American Cancer Society agree that concerns about breast cancer should not influence a women's decision about abortion.

See the NAF (National Abortion Federation) website for further analysis of the breast cancer studies.

According to the New England Journal of Medicine, published in 1997, induced abortions have no overall effect on the risk of breast cancer, based upon a review of the study in Denmark of 1.5 million women.

For more information about Breast Health

Breast cancer is a serious health concern for women. We encourage women to learn all they can about breast cancer prevention and to practice regular self breast exam to know what is normal or what is a change for yourself. Loving our bodies, loving our breasts, and taking care of ourselves is a first step all women can take.

Breast cancer and environmental toxins

National Breast Cancer Coalition

National Alliance of Breast Cancer Organizations

Y-ME National Breast Cancer Organization

Cancer Prevention Ideas at www.preventcancer.com

Center for Reproductive Law and Policy - "Beyond the Cancer Myth" shows how the anti-choice movement is using an unproven and untrue theory in court cases and legislation restricting access to abortion.

page update: January 6, 2009

In 1964, the World Health Organization concluded that 80% of cancers were due to human-produced carcinogens; in 1979, the National Institutes of Health identified environmental factors as the major cause of most cancers. Yet, only a tiny fraction of the National Cancer Institute budget has gone toward research on prevention.

Feminist Women's Health Center