February 6, 2004

Aspirin's role in reducing risk of colorectal cancer

A new study has found that regular intake of aspirin is associated with a reduced risk of the type of colon polyps that can develop into cancer. Since risk reduction was strongest with aspirin doses higher than those used to prevent cardiovascular disease, however, the researchers say further study is needed to determine for whom the benefits of such treatment would outweigh any potential risks. The report appears in the February issue of Annals of Internal Medicine.

"We would love to have a simple, daily tablet that could reduce the risk of colorectal cancer for everyone, but right now we don't have that," says Andrew Chan, MD, of the MGH Gastrointestinal Unit, the paper's lead author. "Confirming that aspirin, especially at higher doses, may reduce cancer risk, however, is very exciting and opens many avenues of research for better understanding the mechanism of this disease."

Earlier studies suggested that aspirin could reduce the risk of colorectal polyps but had not established the most effective dose. The current report examines data from about 27,000 participants in the Nurses Health Study who reported having endoscopic colon examinations between 1980 and 1998. Those who reported taking aspirin regularly had a 25 percent lower risk of polyps than did women who took no aspirin, with the lowest risk seen among those who took more than two standard aspirin tablets per day.

"Before these findings can be translated into clinical recommendations, we need better ways of identifying exactly who should take aspirin to reduce colorectal cancer risk," says Chan.