Monthly Aspirin Use Linked to Lower Pancreatic Cancer Risk

But the study does not prove if the association is due to the drug or other factors, expert says

MONDAY, April 4 (HealthDay News) -- Taking aspirin even once per month, whether low-dose or full strength, appears to be associated with a marked drop in the risk of developing pancreatic cancer, new research reveals.

The findings, from a team led by Dr. Xiang-Lin Tan, a research fellow at the Mayo Clinic in Rochester, Minn., are slated for presentation Monday at the annual meeting of the American Association for Cancer Research, in Orlando, Fla.

"This provides additional evidence that aspirin may have chemoprevention activity against pancreatic cancer," Tan said in a news release from the association.

But, he cautioned, "the results are not meant to suggest everyone should start taking aspirin once monthly to reduce their risk of pancreatic cancer. Individuals should discuss use of aspirin with their physicians because the drug carries some side effects."

To explore the protective potential of aspirin, the investigators focused on 904 pancreatic cancer patients and just over 1,220 healthy individuals, all of whom were seen at the Mayo Clinic between 2004 and 2010.

All of the study participants were at least 55. Questionnaires were completed to assess aspirin use between the ages of 41 and 60, as well as the use of nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen.

Using aspirin at least once per month was linked to a significant drop in pancreatic cancer risk, the research team concluded, even after accounting for other factors that might affect the finding, such as body-mass index and smoking history.

Those who had once smoked but kicked the habit seemed to experience an even stronger protective effect with respect to aspirin use than those who had never smoked or those who continued to smoke, the study authors noted.

NSAID and acetaminophen use did not, however, have any noticeable impact on pancreatic cancer risk, the authors added.

Dr. Michael Choti, a professor of surgery and oncology with the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University in Baltimore, expressed little surprise with the findings.

"There have been other preclinical findings suggesting that there may be some role for aspirin in inhibiting carcinogenesis, including pancreatic carcinogenesis," Choti noted. "And in other cancers, such as colon cancer, aspirin use has been associated with a reduction in cancer risk."

However, "studies that are not randomized trials are fraught with biases," he cautioned. "Those taking aspirin for a variety of reasons, say for cardiac or other cancer-protective effects, may generally have a better lifestyle, smoke less, eat better, exercise more. So one cannot purely conclude from this kind of study as to whether they are finding a general association between people who take aspirin, or in fact a true causative effect," Choti pointed out.

"But it's very interesting," he added. "And certainly the cost and risk of aspirin use is quite low. And this is compelling evidence to suggest there is some benefit, and it's perhaps another reason to advocate the use of aspirin."

Because the study was presented at a medical meeting, the findings should be viewed as preliminary until they are published in a peer-reviewed journal.

More information

For more on pancreatic cancer, visit the American Cancer Society.