Long-Term Daily Aspirin Cuts Cancer Deaths, Study Suggests

Dec. 6, 2010— -- Taking a daily aspirin may do more than lower your heart disease risk -- it could lower your risk of death from cancer as well.

So says a new review of studies published today. Still, many doctors say more must be known about the reasons for the possible benefit before their advice to their patients will change.

Researchers found that after five years, cancer death rates were 21 percent lower in patients assigned to take an aspirin a day -- a reduction in cancer risk that persisted for 20 years -- according to pooled data on a total of 25,570 individuals participating in eight randomized studies.

The meta-analysis, led by Peter M. Rothwell of John Radcliffe Hospital in Oxford, England, was published online in the journal The Lancet.

The researchers called the results "the first reliable evidence that aspirin prevents non-colorectal cancer in humans" -- a possibility to which earlier studies had pointed -- though the preventive effect was evident mainly in deaths from gastrointestinal cancers.

The researchers also said the findings may alter the way doctors view the benefits of daily aspirin in patients in light of the bleeding risk -- albeit a relatively small one -- associated with taking the drug.

"Our analyses show that taking aspirin daily for five to 10 years would reduce all-cause mortality (including any fatal bleeds) during that time by about 10 percent," the researchers wrote.

Mary Beth Terry, an associate professor at the Columbia Mailman School of Public Health in New York, said the findings are consistent with previous research that showed that aspirin prevents colorectal cancer.

"This builds on a very large body of evidence from observational studies suggesting that aspirin can reduce cancer risk of many different tumor sites, but because it analyzes individual data from randomized clinical trials it is very compelling," she said.

Rothwell and colleagues also cautioned, however, that the findings by themselves do not prove that aspirin prevents cancer or even cancer death. They said additional studies would be needed to determine what effect, if any, daily aspirin has on cancer incidence -- as well as the reason for this apparent effect.