CCQ Statement on Reported Link Between Abortion and Breast Cancer

There is no proven link between abortion and breast cancer.

Early studies in the 1950s suggested there may have been an association, but these were later found to be biased, with women diagnosed with breast cancer more likely to volunteer information that they had an induced abortion than healthy women to whom the women with breast cancer were compared.

Larger studies have since been undertaken, including a large Nurses’ Health Study at Harvard University and a population-based study in Denmark, and these did not find a link between abortion and breast cancer risk.

International expert epidemiologist Associate Professor Karin Michels, of the Harvard Medical School and Harvard School of Public Health, is lead author of one of the largest studies in this area. She advises:

“The currently available evidence that is methodologically sound does not suggest an association between induced abortion and breast cancer risk. While there are a number of case-control studies that seem to suggest a link between induced abortion and the risk of breast cancer, these studies are all plagued by the same bias: that women with breast cancer are more likely to volunteer the information that they had an induced abortion than healthy women to whom the women with breast cancer are compared. Many cohort studies have not suggested any link between induced abortion and breast cancer risk, including our data from the very large Nurses’ Health Study at Harvard University in Boston. The methodologically strongest data, however, were collected in Denmark, where the entire female Danish population was included in the study. Since information on induced abortion is captured by a registry in Denmark this meant an objective source of information about which women had had an induced abortion was available. This study, which included 1.5 million women, did not suggest an association between induced abortion and the incidence of breast cancer.”

Cancer Council Queensland relies on the latest evidence available, which does not suggest an association between abortion and breast cancer.

We encourage all Queenslanders to be breast aware, and to visit a GP if you notice any changes to the normal look and feel of your breasts.

If you have any questions about the link between abortion and breast cancer, or reducing your breast cancer risk, please call Cancer Council Helpline 13 11 20, Monday to Friday, 8am to 6pm.