Men who take a daily dose of aspirin or similar anti-inflammatory medicine may also reduce their risk of developing prostate cancer, researchers said.

The study, presented today at an American Association for Cancer Research meeting, found that men who regularly used anti-inflammatory pain pills had a 13 percent lower risk of prostate cancer and 17 percent fewer dangerous, high-grade tumors. A second study suggested the mechanism responsible for preventing the tumors could be the medicines ability to block production of a hormone that spurs cancer growth.

Low-dose aspirin is taken by millions of Americans to prevent heart attacks and strokes, said Pierre Massion, a professor of medicine and cancer biology at Vanderbilt University School of Medicine in Nashville who worked on the research. It has been shown to prevent colon cancer. What we are saying is that the benefit of aspirin even at low doses could also help other cancers, including lung, breast and prostate.

While promising results have been shown in studies of other tumor types, people generally dont take aspirin to prevent cancer or slow its growth. One obstacle was that researchers didnt know how aspirin worked on tumors. The new findings help answer those questions, Massion said in a telephone interview.

We found the mechanism to explain how low-dose aspirin can eventually decrease the incidence of new cancers after you have taken it for five years or more, he said. It can also explain why people who are taking aspirin after being diagnosed have a lower risk of dying of their metastases.

Massions laboratory study showed aspirin inhibited production of Cox-2, which then reduced levels of a prostaglandin called PGE2 that spurs cancer metastases. The findings mean aspirin doesnt only prevent blood platelets from sticking together, the primary way it helps reduce heart attacks. At the cellular level, it can also block Cox-2 in cancer, he said.

Studies to prevent prostate and other cancers with Merck & Co.s Vioxx, a pain medicine that blocked Cox-2, were halted after the drug was pulled from the market because of its heart disease risks. Pfizer Inc. hasnt developed its Cox-2 inhibitor Celebrex for prostate cancer, though it is approved to treat a rare condition where intestinal polyps can lead to colon cancer.

Adriana Vidal, an assistant professor at Duke University School of Medicine and the lead author of the study that looked at prostate cancer rates, said more research is needed. The drugs have side effects, including gastrointestinal bleeding, which have to be weighed against the benefits, she said. The study was based on the patients self-reported use of aspirin and pain medicine.

To contact the reporter on this story: Michelle Fay Cortez in Minneapolis at mcortez@bloomberg.net

To contact the editors responsible for this story: Reg Gale at rgale5@bloomberg.net Drew Armstrong, Andrew Pollack

Original post:

Daily Dose of Aspirin May Cut Prostate Cancer Risk: Study