Research Article Case–Control Study of Aspirin Use and Risk of Pancreatic Cancer

Background: Pancreas-cancer prognosis is dismal, with 5-year survival less than 5%. Significant relation-ships between aspirin use and decreased pancreas-cancer incidence andmortality have been shown in four of 13 studies. Methods: To evaluate further a possible association between aspirin use and risk of pancreatic cancer, we used data from a population-based Connecticut study conducted from January 2005 to August 2009, of 362 pancreas-cancer cases frequency matched to 690 randomly sampled controls. Results: Overall, regular use of aspirin was associated with reduced risk of pancreatic cancer [odds ratio (OR), 0.52; 95 % confidence interval (CI), 0.39–0.69]. Increments of decreasing risk of pancreatic cancer were observed for eachyear of low-doseor regular-dose aspirinuse (OR, 0.94; 95%CI, 0.91–0.98 andOR, 0.98; 95%CI, 0.96–1.01, respectively) and for increasing years in the past that low-dose or regular-dose aspirin use had started (OR, 0.95; 95 % CI, 0.92–0.99 and OR, 0.98; 95 % CI, 0.96–1.00, respectively). Reduced risk of pancreatic cancerwas seen inmost categories of calendar timeperiod of aspirin use, for both low-dose aspirin and regular-dose aspirin use. Relative to continuing use at the time of interview, termination of aspirin usewithin 2 years of interview was associated with increased risk of pancreatic cancer (OR, 3.24; 95 % CI, 1.58–6.65). Conclusions:Our results provide some support that a daily aspirin regimenmay reduce risk of developing pancreatic cancer. Impact: Long-term aspirin use has benefits for both cardiovascular disease and cancer, but appreciable bleeding complications that necessitate risk–benefit analysis for individual applications. Cancer Epidemiol Biomarkers Prev; 23(7); 1–10. 2014 AACR