BOSTON -- A study suggests that taking aspirin often might raise the risk of pancreatic cancer. But other studies indicate that aspirin use lowers the risk of more common cancers. So researchers take the new aspirin finding with a grain of salt.

The study, conducted by researchers at Brigham and Women's Hospital and Harvard Medical School, included data from 88,378 women who participated in the Nurses' Health Study. Among the who were initially cancer-free, 161 cases of pancreatic cancer were found after 18 years.

The researchers found that women who reported taking two or more aspirin tablets a week for 20 or more years had a 58 percent increased risk of pancreatic cancer. But an earlier study had found aspirin reduced the risk.

And pancreatic cancer is rare, while studies have indicated that aspirin can reduce the risk of more common diseases, such as colon cancer. It has also been linked with reduced risks of heart attacks, strokes, dementia, Alzheimer's disease and cataracts.

"These findings, if confirmed, add another variable to the complex risk-benefit profile of aspirin," said lead researcher Dr. Eva Schernhammer, who presented the study Monday at a meeting of the American Association for Cancer Research.

Schernhammer said women should not stop taking aspirin because of the study's findings, but should consult their doctor if they have concerns.