Does Low-Dose Aspirin Reduce Risk of Breast Cancer?

Low-dose aspirin may help women reduce their risk of developing breast cancer, a new study published in Breast Cancer Research has suggested.¹ Overall, regular low-dose aspirin use (81 mg) was tied to a 16% lower risk of breast cancer in women when taken at least 3 times per week.

The study, led by Leslie Bernstein PhD, included women who worked in California public schools. Participants completed a baseline questionnaire from 1995-1996 based on family history of cancer and other conditions, use of NSAIDs, menstrual and reproductive history, self-reported weight and height, living environment, diet, alcohol use, and physical activity. From 2005-2006, 57,164 participants provided updated information, and 1457 of these participants developed invasive breast cancer before January 2013.

The results demonstrated a reduced risk of HR-positive/HER2-negative breast cancer in women taking low-dose aspirin regularly. This study was different from previous research because it examined dose levels and dose frequency, as well as its effect on the subtypes of breast cancer.

“The study found an interesting protective association between low-dose aspirin and breast cancer,” lead author Christina A. Clarke, PhD, MPH, from the Cancer Prevention Institute of California, said in a press release about the study.² “We did not by and large find associations with the other pain medications like ibuprofen and acetaminophen.”

Higher-dose aspirin was not found to be associated with reduced risk of breast cancer, likely because it is typically only taken sporadically for headaches.

Research reported in Breast Cancer Research was supported through grants from the National Cancer Institute and the California Breast Cancer Research Fund.

Reference

• Clarke CA, Canchola AJ, Moy LM, et al. Regular and low-dose aspirin, other non-steroidal anti-inflammatory medications and prospective risk of HER2-defined breast cancer: the California Teachers Study. Breast Cancer Research. 2017. 19:52. doi:10.1186/s13058-017-0840-7.
• Aspirin found to lower risk of breast cancer, City of Hope study suggests [news release]. City of Hope’s website. https://www.cityofhope.org/aspirin-found-to-lower-risk-of-breast-cancer-city-of-hope-study. Accessed May 4, 2017.