Effect of statins as a secondary chemopreventive agent among individuals with non-muscle-invasive bladder cancer: A population-based analysis

Background: Non-muscle-invasive bladder cancer (NMIBC) is especially prevalent among the elderly. Many patients with NMIBC also have significant concomitant comorbidities, including cardiovascular diseases and hypercholesterolemia. Statins are the most commonly used cholesterol-depleting agents, and they may possess anticancer properties. The objective of this population-based study was to evaluate the effect of statins on the survival of individuals diagnosed with NMIBC.

Methods: This is a retrospective population-based cohort study that used administrative databases to identify individuals 66 years of age and older who were diagnosed with NMIBC between 1992 and 2012. Subjects with documented use of statins before they were 66 years of age were excluded from the analysis. Cumulative daily use of statins was calculated before and after the diagnosis of NMIBC. Their effect on cancer-specific survival and overall survival was estimated using a multivariable competing risk and Cox proportional hazards model, respectively.

Results: The final cohort was composed of 13,811 individuals≥66 years diagnosed with NMIBC. Of these, 4,748 individuals (34%) were exposed to statins during follow-up. The median statin exposure after NMIBC diagnosis was 21.4 months (interquartile range: 7.8-45.4). After a median follow-up of 7.1 years (interquartile range: 4.0-11.3) from NMIBC diagnosis, 8,900 (64%) individuals had died. The cumulative use of statins after NMIBC diagnosis did not significantly affect cancer-specific survival (P = 0.10). However, its cumulative use after NMIBC diagnosis was associated with a better overall survival ([0.93; 95% CI: 0.91-0.96], per year of use).

Conclusions: This large population-based study has provided evidence that cumulative statin use was not associated with an improved cancer-specific survival among individuals with NMIBC. However, our findings did demonstrate that statin users had a better overall survival than nonusers.