NEW YORK (Reuters Health) - Abortion does not affect the risk of breast cancer, according to study findings published in the International Journal of Cancer.
"It is well established that pregnancies that end in a full-term birth ultimately confer a protective effect on breast cancer risk," Dr. Gillian K. Reeves, of the University of Oxford, UK, and colleagues write. "The effect of incomplete pregnancies on the risk of breast cancer has been less clear."
The researchers therefore examined the role of abortion on breast cancer risk among 267,361 women enrolled in the European Prospective Investigation into Cancer and Nutrition between 1992 and 2000. The data came from 20 centers across nine countries.
The women were followed for an average of 6.6 years. A total of 4805 women were diagnosed with breast cancer during follow-up. The researchers included all pregnancies that ended prior to 20 weeks or the stage of viability - spontaneous abortions (also referred to as miscarriage) and therapeutic or induced abortions.
"Overall, almost two thirds of women reported never having had any type of abortion, while about one third reported having had at least one type of abortion," Reeves and colleagues report.
Approximately 20 percent reported having a spontaneous abortion compared with about 16 percent who reported having an induced abortion. Only 3.8 percent of women reported having both types of abortion.
Having one spontaneous abortion did not affect the risk of breast cancer and having two or more spontaneous abortions only slightly increased the risk. No evidence of a relationship between one or more induced abortions and breast cancer was found.
"Overall, the findings provide further unbiased evidence of the lack of an adverse effect of induced abortion on breast cancer risk," the team concludes.
SOURCE: International Journal of Cancer, October 1, 2006.
Research has shown that women who have had at least one full-term pregnancy have a lower risk of breast cancer. In other words, having at least one baby after being pregnant for nine months lowers your breast cancer risk. Because of this protective effect of full-term pregnancy, some researchers wondered whether birth control pills or abortion would also have an effect on breast cancer risk.
Researchers at the Centers for Disease Control looked at the first part of the question and their results showed that taking birth control pills DOES NOT increase a woman's risk of breast cancer.
Now, the study reviewed here shows that women who have had one miscarriage (spontaneous abortion) or one or more induced abortions DO NOT have a higher risk of breast cancer. Women who had two or more miscarriages had a slight increase in risk. The researchers didn't explain why this slight increase in risk happened.
Abortion is a very sensitive topic. This study supports earlier evidence that having an induced abortion or miscarriage does not increase a woman's breast cancer risk. We hope that by reviewing this study and others on this sensitive topic, we can help you feel more informed and secure about important health decisions you may face.
Breastcancer.org 7 East Lancaster Avenue, 3rd Floor Ardmore, PA 19003
Learn more about our commmitment to your privacy
© 2008 Breastcancer.org - All rights reserved.
Breastcancer.org is a non-profit organization dedicated to providing information and community to those touched by this disease. Learn more about our commitment to providing complete, accurate, and private breast cancer information.