Aspirin May Lower Risk of Pancreatic Cancer

Daily aspirin may reduce the risk of developing pancreatic cancer.

A new study provides evidence that a daily aspirin may reduce the risk of developing pancreatic cancer. The research, published in Cancer Epidemiology, Biomarkers & Prevention, shows that the longer a study participant used aspirin, the lower his or her risk of developing pancreatic cancer became. This study was funded by the National Cancer Institute.

The study, which was conducted from January 2005 to August 2009, showed that those who took a daily aspirin had a 48% relative risk reduction of pancreatic cancer, after controlling for factors such as age, smoking history, diabetes, race, sex, and other medical history factors.

For each year of either regular or low-dose aspirin use, the study authors observed an incremental decrease in risk of pancreatic cancer (odds ratio of 0.98 and 0.94, respectively). Compared with those who continued regular use of daily aspirin, those who discontinued use within 2 years of study assessment had an increased risk of pancreatic cancer (odds ratio of 3.24). Low-dose aspirin was defined as 75 to 325 mg daily.

Harvey A. Risch, MD, PhD, of the department of epidemiology and public health at the Yale School of Public Health in New Haven, Connecticut, and colleagues analyzed data from a Connecticut population study of 362 pancreatic cancer patients matched with 690 randomly chosen controls. Compared with the controls, pancreatic cancer patients were slightly older, less educated, more likely to be current or recent smokers, and more likely to have been diagnosed with diabetes at least 3 years before being evaluated on this study.

Those who took aspirin for 3 to 5 years reduced their risk of pancreatic cancer by 48%, and those who took any type of aspirin for more than 20 years reduced their risk by 60%. Reduction of risk ranged from 39% for those who took low-dose aspirin for 6 years or less, to 60% for those who took low-dose aspirin for more than 10 years.

Some patients currently take aspirin regularly to lower their risk of heart disease, heart attack, or stroke. Studies have also shown that regular aspirin use can lower the risk of developing other cancer types, including colon cancer. But, epidemiological studies linking aspirin use to lower cancer risk are not consistent.

Risch emphasized that because regular aspirin use has its own risks, the choice to use aspirin regularly as a preventive measure is individual and should be based on medical history and other considerations. “For the small subset of individuals with strong family histories of pancreatic cancer or who otherwise have been evaluated to be at substantially increased risk of pancreatic cancer, aspirin use could be part of a regimen designed to reduce their risk,” said Risch in a statement.

Whether aspirin may help to prevent pancreatic tumor formation or facilitates the control of small tumors through the immune system, or whether the drug acts by a different mechanism or combination of mechanisms, is unclear. Further follow-up studies to assess the impact of daily aspirin on pancreatic cancer risk are still necessary.