This is the VOA Special English Health Report

People since ancient times have used aspirin-like medicines to fight pain and reduce high body temperature.

Boxes of aspirin at a drugstore in Chicago

Modern research has found other uses for aspirin. The drug acts as a blood thinner. It can help blood flow past a blockage in an artery. Blockages can cause heart attacks or strokes. As a result, patients at risk of blockages might be advised by their doctors to take a low-strength aspirin every day.

And research continues. A new study has shown that aspirin can improve survival in colon cancer patients.

It involved about one thousand three hundred patients with colorectal cancer. The cancer had not spread to other parts of the body yet. The study compared patients who took three hundred twenty-five milligrams of aspirin at least two times a week with those who did not use aspirin.

The study found that the aspirin users had an almost thirty percent lower risk of dying from their cancer. That was during an average of eleven years after the cancer was discovered.

Andrew Chan of Harvard Medical School and Massachusetts General Hospital led the study. Doctor Chan says the effects appeared especially strong among patients with tumors expressing an enzyme called COX-2. Two-thirds of colorectal cancers produce that chemical. Doctor Chan thinks the aspirin works by blocking it. 

The study appeared last week in the Journal of the American Medical Association. It was an observational study. In a controlled study, some patients would have taken aspirin. Others would have received a placebo -- sugar pills -- for comparison.

Last year, Doctor Chan reported that a long-term study of almost fifty thousand men showed that aspirin can help prevent colon cancer. But the effects required at least six years of regular use. And the greatest risk reductions were in those who took more than fourteen aspirins per week.

But the researchers warned that the dangers from such large amounts of aspirin should be carefully considered.

Aspirin is a kind of nonsteroidal anti-inflammatory drug, or NSAID. The earlier study found comparable reductions from the use of other NSAIDs, but not from the use of acetaminophen.

All of these drugs have their uses but they also have risks. Aspirin can cause bleeding in the stomach, the intestines and the brain. People who might want to consider taking aspirin as a preventative measure should first talk to a doctor.

And that's the VOA Special English Health Report, written by Caty Weaver and available at voaspecialenglish.com. I'm Steve Ember.