Aspirin may prevent heart attacks, but probably not cancer

While low-dose aspirin may help prevent heart disease, a randomized, placebo-controlled study of almost 40,000 women finds that alternate day use of 100 mg aspirin for an average of 10 years does not lower the risk of total, breast, or colorectal cancer.

The study, which is the longest of any trial on this matter to be completed to date and which is part of the Women's Health Study, did show a trend toward reduction in the risk of lung cancer that was significant for lung cancer deaths, but the findings require confirmation.

Whether higher doses of aspirin confer protective benefits, as some previous studies have indicated, cannot be ruled out.