Statin prescribing and long-term survival among Korean cancer survivors: A nationwide population-based cohort study (STROBE compliant)

Cancer survivorship is rapidly increasing in Korea, and long-term outcomes are influenced not only by cancer progression but also by competing risks such as cardio-cerebrovascular disease. Statins, routinely prescribed for cardiovascular prevention, have pleiotropic anti-inflammatory and immunomodulatory properties and have been suggested to affect outcomes in patients with cancer. We investigated whether statin prescription was associated with long-term all-cause mortality using data from Korean nationwide health insurance claims. Patients were divided into 4 groups based on the duration of statin prescription: nonusers, T1, T2, and T3. Kaplan-Meier estimates and log-rank tests were performed to compare the survival rate among the 4 groups. Cox proportional hazards regression models were constructed for all-cause mortality. Among 154,916 patients, the median follow-up was 14.6 years, and the cumulative survival was lowest in statin nonusers and highest in T3 in both sexes (log-rank P < .001). After full adjustment, hazard ratios (95% confidence intervals) for all-cause mortality of T1, T2, and T3 were 0.637 (0.619-0.658), 0.482 (0.462-0.503), and 0.258 (0.244-0.272), respectively, in men and 0.608 (0.580-0.637), 0.406 (0.385-0.430), and 0.190 (0.178-0.203), respectively, in women. Similar inverse associations were observed across most major cancer types. In this nationwide cohort of Korean cancer survivors, statin prescription duration was associated with lower all-cause mortality. Given the observational design and the potential for residual confounding and immortal time bias, these findings should be interpreted cautiously.