Low-dose aspirin taken every other day lowers the risk for colorectal cancer in middle-aged women, according to an Annals of Internal Medicine study.
Nearly 40,000 women aged 45 and older were randomized to take low-dose aspirin (100 mg) or placebo every other day for roughly 10 years; 84% were followed for an additional 7 years after treatment ended.
During the total follow-up, colorectal cancer risk was lower in the aspirin group (hazard ratio, 0.80), mostly owing to a reduction in proximal colon cancer, which emerged after 10 years. The incidence of total, lung, or breast cancer did not differ between the groups. Gastrointestinal bleeding and peptic ulcers occurred more often with aspirin.
An editorialist says that while aspirin may have a chemopreventive role in high-risk patients, the increase in bleeding and lack of effect on total cancer or all-cause mortality "should temper any recommendations for widespread use ... in healthy middle-aged women."