Abortion and breast cancer
There are a number of risk factors for developing breast cancer including changes in hormone levels throughout a woman’s life. Levels of hormones can change a great deal during pregnancy.
When a woman is pregnant, her body begins to prepare for breast feeding by altering the levels of hormones. This causes changes to breast tissue. Concern about a possible link between abortion and breast cancer has been raised because it is thought to interrupt the normal cycle of hormones during pregnancy.
The Canadian Cancer Society’s perspective
At the present time, the body of scientific evidence does not support an association between abortion and increased breast cancer risk.
We base this perspective on the findings from a workshop of over 100 of the world’s leading experts who study pregnancy and breast cancer risk. The workshop was organized by the US National Cancer Institute and it took place in 2003. The experts reviewed existing human and animal studies on the relationship between pregnancy and breast cancer risk. Among their conclusions were:
- induced abortion is not associated with an increase in breast cancer risk
- spontaneous abortion (miscarriage) is not associated with an increase in breast cancer risk
The Canadian Cancer Society is committed to conveying important information about breast cancer risk to Canadian women. We will continue to closely monitor high-quality, peer-reviewed research findings about this topic and will update our information if warranted.
Women who have had an induced or spontaneous abortion (miscarriage) should follow the same breast cancer screening guidelines as women who have not.
For more information
US National Cancer Institute – Abortion, Miscarriage, and Breast Cancer Risk
American Cancer Society – Is Abortion Linked to Breast Cancer?