Low-Dose Aspirin Lowers Risk of Colon Cancer

Q. I have read that taking aspirin can lower the risk of getting cancer. When I asked my doctor about this he dismissed it as a chance finding and not a controlled study. What’s the story?
A. The most recent analysis of aspirin’s protective effects against colorectal cancer was published in The Lancet (online, Oct. 22, 2010). The investigators followed over 14,000 subjects from five randomized trials over 20 years. They found that people who took 75 mg of aspirin daily for five years reduced their risk of colon cancer by about 70 percent.
This kind of study is the gold standard in that subjects were randomized to receive either aspirin or placebo. Of course, no one should start taking aspirin daily without medical supervision. Even low doses can cause ulcers.