Statin use and mortality among endometrial cancer patients: a Danish nationwide cohort study

Statin use has been linked to improved prognosis of some cancer types, however, for endometrial cancer, the results are equivocal. We therefore examined the effect of statin use on endometrial cancer mortality. From the Danish Cancer Registry, we identified all women in Denmark aged 30-84 years with primary endometrial cancer during 2000-2012. Data on drug use, mortality outcomes and potential confounders were retrieved from nationwide registries. We used Cox proportional hazards regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for endometrial cancer-specific and other-cause mortality associated with statin use. Among 6,694 endometrial cancer patients, 753 died from endometrial cancer and 765 from other causes during a median follow-up of 4.5 year (interquartile range: 1.9-8.1). We observed an inverse association between time-varying postdiagnosis statin use (>= 2 prescriptions) and endometrial cancer mortality (HR: 0.61, 95% CI: 0.48-0.77) compared to non-use (<2 prescriptions). The associations did not differ substantially by intensity or cumulative amount of statin use. In secondary analyses including prediagnosis statin use, we observed reduced mortality among both continuing (pre- and postdiagnosis) users (HR 0.70, 95% CI 0.53-0.92) and new (postdiagnosis only) users (HR 0.43, 95% CI 0.29-0.65) compared to "never users." In sensitivity analyses with fixed exposure periods after the endometrial cancer diagnosis, the inverse association was more pronounced more than 5 years after the diagnosis. Our findings suggest that statin use may be associated with improved survival in endometrial cancer patients.