Does aspirin use reduce the risk for cancer?

Recently, studies have reported that aspirin has chemopreventive properties. In this study, we used the Taiwan NHI database, which covers a population of 23 million (99.99%) Taiwanese from 2001 to 2011. This was a case-control study which identified 601,733 patients using ICD-9-CM codes who were diagnosed with cancer. Each case with 4 eligible controls was matched for age, sex, and index date and adjusted for confounding factors. The observed overall cancer risk (adjusted OR (AOR), 0.95; 95% CI 0.94 to 0.96) reduced with aspirin use, specifically, colorectal (AOR, 0.97; 95% CI 0.94 to 0.99) and digestive system (AOR, 0.96; 95% CI 0.94 to 0.98) cancers. Findings from the Asian population would contribute to the discussion on aspirin's safety profile.