The Association of Aspirin Use with Survival Following Radical Cystectomy

Purpose: Aspirin may have antineoplastic properties through the inhibition of inflammatory cytokines that regulate cell proliferation, angiogenesis and apoptosis. In patients with nonmuscle invasive bladder cancer aspirin use has been linked to a reduced risk of recurrence. We evaluated the association of aspirin with survival following radical cystectomy. Materials and Methods: A total of 1,061 patients underwent radical cystectomy at our institution between 2007 and 2016, of whom 461 (43%) were aspirin users at the time of surgery. Survival estimates were assessed by the Kaplan-Meier method. The Cox proportional hazards model was applied to evaluate associations between patient features and survival. Results: Median followup after radical cystectomy among survivors was 4.2 years (IQR 2-6.2). During this time 442 patients died, including 331 of bladder cancer. Aspirin users were significantly older, more likely to have a history of cardiovascular disease and diabetes, and more likely to use metformin or statin (each p <0.05). Nevertheless, we found that patients who ingested a daily aspirin had significantly higher 5-year cancer specific survival (68% vs 60%, p = 0.02) and overall survival (59% vs 52%, p = 0.03) compared to nonusers. Moreover, after multivariable adjustment aspirin use remained independently associated with lower cancer specific mortality (HR 0.64, 95% CI 0.45-0.89, p = 0.01) as well as all cause mortality (HR 0.70, 95% CI 0.53-0.93, p = 0.02) but not with distant metastasis (p >0.05). Conclusions: Daily aspirin use was associated with significantly improved survival outcomes following radical cystectomy. Further research is warranted to evaluate the potential underlying biological mechanisms and investigate causality.