That's the finding of a British study of people with Lynch syndrome, an inherited condition that accounts for about 3 to 5 percent of colon cancer cases.
Researchers say those who took daily aspirin for at least two years developed fewer cases of colon cancer.
A cancer prevention expert at the U.S. National Cancer Institute who was not linked to the study calls it good news for a very specific population. He says the finding could apply to about 15 percent of colon cancer patients who have genetic defects similar to Lynch syndrome.
But daily aspirin isn't recommended for the general public because of side effects such as gastrointestinal bleeding.
One of the groups paying for the study was aspirin maker Bayer.
The findings were published in the journal Lancet.