Dr. Michelle D. Holmes of the Channing Laboratory at Harvard and Brigham and Women's Hospital in Boston, and colleagues found an aspirin at least two days a week significantly reduced breast cancer death risk by 64 percent to 71 percent, Medpage Today reported Tuesday.
The analysis included responses from 4,164 female registered nurses diagnosed with early stage breast cancer from 1976-2002 with follow-up through death or June 2006.
Holmes said aspirin use assessments in the first year after the breast cancer diagnosis were excluded since the drug is discouraged during chemotherapy.
For the women who survived for more than a year after diagnosis, those who used aspirin more were less likely to subsequently die from breast cancer, the study said.
The findings, published in the Journal of Clinical Oncology, were "all the more notable because the Nurses' Health Study did not find an association between aspirin use and breast cancer incidence."
However, aspirin and other non-steroidal anti-inflammatory drugs may help prevent the spread of cancer once cancer occurred by reducing the blood supply to tumors. Aspirin isn't risk-free and can cause gastrointestinal bleeding, and further research is needed, the researchers warned.