Aspirin for Preventing Colorectal Cancers and Other Solid Tumors

Taking ≥500 mg of aspirin daily for at least 5 years significantly lowers risk for incident colorectal cancer more than 10 years later, but this regimen carries too much gastrointestinal risk to be useful for prevention. A pair of meta-analyses demonstrated convincingly that lower-dose daily aspirin, taken for at least 5 years, lowers long-term risk not only for incident colon cancer but also for death caused by colon cancer and other solid tumors. Both new analyses relied on long-term mortality and cancer registry data collected in the U.K. after four controlled trials of aspirin versus placebo for prevention of adverse cardiovascular events.

In one meta-analysis, 14,000 patients had received study-dose aspirin or placebo for a mean of 6 ye…