To the Editor We read with interest the recent article by Jackson et al1 in JAMA Oncology on aspirin (acetylsalicylic acid) therapy in patients with biliary tract cancer (BTC). The authors conducted a retrospective cohort study using data from the UK’s Clinical Practice Research Datalink (CPRD) to test the hypothesis that aspirin’s anti-inflammatory mechanism may slow the spread of BTC. Analysis of overall survival was stratified by aspirin prescription and BTC subtype. The results are impressive, with adjusted mortality hazard ratios ranging from 0.44 to 0.71, all statistically significant. Kaplan-Meier survival estimates showed that median overall survival was barely reached in the aspirin cohort. These results were interpreted to show that the survival benefit of aspirin is on par with the current standard therapy for BTC.1 We commend the authors on this innovative, thought-provoking research.