Aspirin Use and Reduced Risk of Pancreatic Cancer

Abstract

Background Few options beside avoidance of smoking and obesity are available to prevent pancreatic cancer. The association between aspirin use and risk of pancreatic cancer has been inconsistent across studies. Methods We performed a population-based study of 761 case and 794 control subjects frequency matched on sex and age during 2006–2011 in Shanghai, China. Participants were asked about episodes of regular use of aspirin, tablets per day or week, and ages that use started and stopped. Data were analyzed by unconditional logistic regression, with adjustments for age, sex, education, body-mass index, years of cigarette smoking, cigarettes smoked per day, Helicobacter pylori CagA seropositivity, ABO blood group, and history of diabetes mellitus. Meta-regression was carried out to summarize the literature. Results Ever-regular use of aspirin was associated with lowered risk of pancreatic cancer: odds ratio [OR] = 0.54; 95% CI, 0.40–0.73, P=10−4.2. Risk decreased 8% per each cumulative year of use: ORtrend = 0.92; 95% CI, 0.87–0.97; P=.0034. Across this and 18 published studies of this association, the OR for ever-regular use decreased with increasingly more recent mid-study year, for any aspirin type (Ptrend=10−5.1), and for low-dose aspirin (Ptrend=0.0014). Conclusion Regular use of aspirin thus appears to reduce risk of pancreatic cancer by almost half. Impact People who take aspirin for prevention of other diseases likely also reduce their risk of pancreatic cancer. Aside from benefits for both cardiovascular disease and certain cancers, long-term aspirin use entails some risks of bleeding complications which necessitates risk-benefit analysis for individual decisions about use.

Low-Dose Aspirin and Pancreatic Cancer Risk—Reply

“…Brasky and Wactawski-Wende note that in Figures 1 and 2 of our paper (1), the years shown with the individual studies do not correspond to the publication years of the papers. This observation is correct; the years are the approximate midpoints of the periods of case collection in each of the studies.…”

“…The second study showed that low-dose aspirin inhibits platelet c-MYC regulation and PANC-1 cancer-cell proliferation (4). If these findings are confirmed, they would provide possible mechanisms for the reduced risk of pancreatic cancer that has been increasingly seen in studies of aspirin use (1). …”

“…Brasky and Wactawski-Wende for their positive and constructive observations about our observed reduced risk of pancreatic cancer with aspirin use (1). The risk relationship is interesting, especially since a number of plausible mechanisms for aspirin involvement in risk have been suggested, but none verified in the human context, including the apparent lack of appreciable anti-inflammatory properties of low-dose aspirin, as they mention (2).…”

Aspirin and Pancreatic Cancer—Response

“…That work suggests that aspirin use may slow the growth of such cysts. If this finding is substantiated, it would provide a mechanism underlying the reduced risk of pancreatic cancer that has been increasingly observed in studies of aspirin use (1). …”

“…I thank Dr. Mormile for her suggestion that our observed reduced risk of pancreatic cancer with aspirin use (1) might arise from down regulation of the anti-apoptosis protein survivin (2). Survivin has been observed to be expressed by cancer tissue but not normal tissue (3).…”