Aspirin Cuts Cancer Deaths, Study Shows: What Dose Is Best?

(CBS) An aspirin a day keeps the cancer away.

That's according to a ground-breaking new study published online yesterday in the journal "The Lancet."

The study, which followed more than 25,000 men and women for 20 years, found that following an aspirin regimen reduced the risk of cancer-related death by 20 percent.

Aspirin was found to be especially effective at preventing gastrointestinal cancers, specifically colorectal cancer. It was also successful at preventing cancer of the lung and esophagus.

Benefits seemed to be greatest for middle-aged people. Dr. Peter M. Rothwell, a co-author of the study and professor of clinical neurology at Oxford University in England, said that those who maintain an aspirin regimen for 20 to 30 years starting in their late 40s might have the greatest chance of avoiding lethal cancer.

So how does aspirin prevent cancer?

Essentially, it encourages precancerous cells to commit cell "suicide," Rothwell told the BBC.

"The cell realizes, as it were, that it's got a problem and it self-destructs," he said. "And there are mechanisms that lead cells to do that, and aspirin appears to encourage those mechanisms."

But don't go popping aspirin like candy. Increasing the daily dosage past 75 mg did not reduce risk of cancer-related death, the study showed. And there are significant risks to taking aspirin daily, such as bleeding and stroke.

So what is the take-away message? "If someone is taking low-dose or regular aspirin it may put them at reduced risk for death from cancer," Dr. Alan Arslan, assistant professor of obstetrics and gynecology and environmental medicine at New York University Langone Medical Center, told CBS News via email.  "However, if someone is not already taking aspirin they should talk with their physician before starting."