Aspirin May Lower Colon Cancer Risk
But It's Too Soon to Recommend It for Prevention
March 5, 2003 -- People who take aspirin to protect their hearts may also be protecting themselves against one of the leading causes of cancer death. Two new studies suggest that an aspirin a day may help prevent the formation of polyps that can lead to colon cancer.
Researchers found that a daily aspirin significantly reduced the recurrence of colon polyps among people with previous colon cancers. A weaker association was seen for patients with a history of polyps but no cancer. But it is too soon to recommend that anyone -- even those at high risk -- take aspirin or any other anti-inflammatory drug solely to lower their colon cancer risk, the researchers say.
The studies appear in the March 6 issue of The New England Journal of Medicine.
"Screening is still the most important thing that people can do to protect themselves against colorectal cancer," lead researcher Robert S. Sandler, MD, tells WebMD. "The worst thing that could happen is for people to get the idea that they don't have to get screened if they take aspirin. But these studies do suggest that aspirin helps prevent the development of colon polyps."
Each year, roughly 57,000 Americans die of colon cancer, making it the second leading cause of cancer deaths overall. The risk of developing colon cancer and the polyps that can lead to the disease increases with age. Nine out of 10 people diagnosed with colon cancer are over the age of 50.
Previous trials attempting to show a protective benefit for dietary fiber, antioxidant vitamins, and diet have proved disappointing. There is some evidence that dietary calcium protects against the formation of polyps, but the findings are not conclusive.
Animal trials and preliminary studies in humans have suggested that regular aspirin use lowers the risk of colon cancer. To further test this theory, Sandler and colleagues recruited more than 1,100 patients with a history of polyps and 635 patients with a history of colon cancer.
The colon cancer patients were treated with a regular, coated aspirin (325 mg) or placebo daily. The trial was stopped early, after roughly 31 months, because the aspirin group had significantly fewer polyps.