Does abortion cause breast cancer?

No. Although there has been a great deal of controversy on this topic, scientists have agreed that abortion does not cause breast cancer.

The world’s leading experts, including epidemiologists, clinical researchers, and basic scientists, have discussed the scientific data on reproductive events in a woman’s life that could affect her risk of developing breast cancer. They evaluated the research that has been done on this topic and concluded that abortion and miscarriage do not increase a woman’s risk of breast cancer.

Breast cancer is related to reproductive experiences such as age of puberty and age of motherhood, and for years anti-abortion activists have cited research showing a link between abortion and breast cancer. That research has been quoted by some politicians as evidence that should be provided to women to discourage abortions. A workshop was held in 2003 (during the Bush Administration) at the National Cancer Institute (NCI) as a result of this controversy, and despite political pressures it concluded that the research linking breast cancer and abortion is flawed and not as credible as research indicating that there is no link between breast cancer and either abortion or miscarriage.

A medical journal article published in 2015¹ evaluated 15 studies on this issue, which included 31,816 women with breast cancer from seven studies in the U.S., seven studies in Europe, and one in China, conducted between 1986 and 2013. The scientists only evaluated studies which used the most reliable research design (what is known as a “prospective study”) and concluded that the evidence does not show a link between cancer and abortion.

The fact that abortion does not increase the risk of breast cancer is also supported by, among others, the World Health Organization (WHO), the National Cancer Institute and the American Cancer Society, as well as many women’s health advocacy organizations, including the National Breast Cancer Coalition, the National Women’s Health Network and Our Bodies Ourselves.

For more information on the NCI workshop and early reproductive events and breast cancer, please see: http://cancer.gov/cancerinfo/ere.