Lead author Kristin Anderson, Ph.D., and her colleagues followed 28,283 American postmenopausal women who were part of a larger study on women's health. The participants were asked how often they took aspirin or aspirin-containing products and how often they took other nonsteroidal anti-inflammatory drugs.

Researchers studied patient medical records, including those of the 80 women who were diagnosed with pancreatic cancer; they found that pancreatic cancer occurred less frequently among women who had reported aspirin use than it occurred in women who had reported they did not use it.

"There is strong evidence to suggest that using aspirin may help in preventing pancreatic cancer, and what's most encouraging is that we've seen these benefits in women who've taken aspirin two to five times per week," said Anderson.

"Based on these observations, we estimate that aspirin use might prevent 43 percent of pancreatic cancer cases in women who do not normally use aspirin. While these results are promising, further studies are necessary to learn more about other factors, such as dose, duration, and types of nonsteroidal anti-inflammatory drugs that may help prevent this disease."

Several previous studies have provided evidence that nonsteroidal anti-inflammatory drugs may lower risk for pancreatic cancer, but this study is the largest to date. The current study did not find an association between use of nonaspirin nonsteroidal anti-inflammatory drugs and incidence of pancreatic cancer.