Low-Dose Aspirin May Lower Breast Cancer Risk

Taking low-dose aspirin at least three times per week may reduce women’s risk of breast cancer by up to 20 percent, a new study suggests. Many people take low-dose aspirin (also called baby aspirin) to reduce the risk of heart disease. A low dose of aspirin is 81 mg per day. Aspirin reduces inflammation and is also a weak aromatase inhibitor. Aromatase inhibitor medicines — Arimidex, Aromasin, and Femara — are used to treat hormone-receptor-positive breast cancer.

Earlier studies have suggested that people who regularly take low-dose aspirin may have a lower risk of breast and some other cancers. Still, these studies didn’t look at whether any possible risk reduction was linked to the characteristics of the breast cancer.

A preliminary study suggests that women who take low-dose aspirin 3 or more times per week have a lower risk of hormone-receptor-positive, HER2-negative breast cancer. The study used data from more than 57,000 women who were part of the California Teachers Study.

In the 23% of women who reported using low-dose aspirin regularly, researchers saw a 20% reduction in the risk of developing HR-positive/HER2 negative breast cancer, some of the most common forms of the disease.

The risk was inversely associated with taking a low-dose aspirin three or more times a week, compared with those women who had no regular low-dose aspirin use. Women who took other nonsteroidal anti-inflammatory medications such as ibuprofen did not see as much of a difference, nor did those taking a regular high-dose aspirin. Previous studies have showed mixed results in breast cancer impact among women who took a regular high-dose aspirin.

The new study did not look at why there might be an association between lower cancer risk and aspirin, but author Leslie Bernstein, a professor in the Division of Cancer Etiology in the Department of Population Sciences at the Beckman Research Institute of the City of Hope Comprehensive Cancer Center, said one reason may be because aspirin can lower inflammation.

“Simply things like obesity or inflammatory conditions are a risk factor for breast cancer, so this may be one reason it could help,” Bernstein said.

Yet, it’s too soon to suggest taking baby aspirin to reduce breast cancer risk.

If more study bears out the link between baby aspirin and breast cancer prevention, Bernstein said low-dose aspirin may also help prevent recurrence.

The study was published online May 1 in the Breast Cancer Research journal. It was funded by the U.S. National Cancer Institute and the California Breast Cancer Research Fund.

Bottom line: People who regularly take low-dose aspirin may have a lower risk of breast cancer and some other cancers.

About the author: Raja P. Reddy, MD is a board certified diagnostic radiologist specializing in breast imaging. He is also a contributing editor for Women’s Imaging Specialists, a leading provider of outpatient women’s imaging services in the greater Atlanta, GA area.