Small Doses Of Aspirin Might Cut Cancer Risk

New studies suggest a small dose of aspirin, taken once a day or even less often, may reduce the risk of colon and rectal cancer, scientists said Tuesday.

And in a surprising but very preliminary finding in mice, another study hints the painkiller also may slow the growth of lung cancer.

The scientists were reluctant to recommend that people take aspirin as a cancer preventive until further research has been done, in part because aspirin has potentially serious side effects in some people. But they were encouraged by the new evidence that only small amounts are necessary.

As little as a twice-a-week dose of the painkiller might be sufficient to reduce the risk of developing colon cancer or dying from it, and taking more than that appears to be ineffective, Dr. Mack T. Ruffin of the University of Michigan Medical School and his colleagues found.

“The scientific importance of this study is that 80 milligrams a day (the amount in one baby aspirin) was enough to block production” of substances in colon and rectal cells that seem to play a part in the development of cancer, Ruffin told a meeting of the American Association for Cancer Research.

The report on aspirin and lung cancer, from Andre Castonguay of Laval University in Quebec, is the first to suggest the drug might help offset the carcinogenic effect of tobacco smoke.

Mice were fed acetylsalicylic acid (the active ingredient in aspirin) or aspirin or sulindac, a prescription anti-inflammatory drug. Then, for seven weeks, the rodents drank water containing NNK, a principal carcinogen in tobacco smoke. The scientists reported that acetylsalicylic acid and aspirin both curbed tumor growth by about 60 percent, while sulindac cut it by 53 percent.