Aspirin Might Help Combat Cancer
High doses needed for benefit, though, and carry high risks

(HealthDay News) -- Aspirin has a history of helping. Since 1829, when it was discovered that a compound in willow plants could provide pain relief, scientists have perfected and expanded its use to battle fever, pain, swelling and blood clots. It's become an important tool in the fight against heart attacks and stroke.

Now researchers believe it might protect against some cancers, too.

A study by American Cancer Society researchers found that taking an aspirin every day lowered the odds of colon, prostate and breast cancer for people at high risk for those malignancies.

"Men and women who used adult-strength aspirin daily for five or more years had about a 15 percent lower overall rate of developing cancer, particularly colon, prostate and possibly breast cancer," lead author Eric Jacobs, strategic director of pharmacoepidemiology at the American Cancer Society, told HealthDay .

But there might be a catch.

There's not enough evidence that aspirin's value as a cancer preventive outweighs its potential toxic side effects, which include a higher risk for bleeding, the researchers said.

"There really aren't any immediate clinical implications" to the study results, he said. "The American Cancer Society doesn't recommend using aspirin to prevent cancer, because aspirin can cause serious gastrointestinal bleeding." That might change, he said, if additional studies produce similar results.

In the study, Jacobs and his team looked for a link between long-term use of aspirin -- dosed at 325 milligrams or more a day -- and cancer in about 146,000 men and women. In a 12-year period, more than 18,000 of them were diagnosed with cancer.

The researchers found that taking daily aspirin for at least five years was associated with about a 15 percent relative reduction in overall cancer risk. The risk of prostate cancer was 20 percent lower, and colorectal cancer 30 percent lower, among those who took aspirin than among those who didn't.

At least for now, though, medical experts seem to support caution.

"The jury is still out about making recommendations about aspirin for the prevention of cancers -- even those cancers where we do see significant protection," Maria Elena Martinez, co-director of the Arizona Cancer Centers Cancer Prevention and Control Program, told HealthDay .

Martinez said that although low daily doses of aspirin have shown to be helpful when used to lower the risk of heart attack, clot-related strokes and other blood-flow problems, cancer protection has been seen only when high doses are taken.

"It's with the higher doses where we see the toxicity and side effects," she said.

"If there were evidence that aspirin protected against a multitude of cancers, then we might get to the point where we'd say it's time to start considering it," Martinez said. "But you have to keep in mind that it comes with side effects. At this point, we are not ready to say, 'Take aspirin,' as we do with cardiovascular disease."

On the Web

To learn more about aspirin and cancer prevention, visit the U.S. National Cancer Institute.

SOURCES: HealthDay News ; Eric Jacobs, Ph.D., epidemiologist, American Cancer Society, Atlanta; Maria Elena Martinez, Ph.D., Arizona Cancer Center, Tucson; April 18, 2007, Journal of the National Cancer Institute
Author: Anne Thompson
Publication Date: April 30, 2008
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