Objectives: To assess the impact of statin use on survival outcomes in the phase III SPARTAN trial of apalutamide for nonmetastatic castration-resistant prostate cancer.
Subjects and methods: We analyzed data from all 1,207 SPARTAN participants, identifying baseline statin users and matching them 1:1 to nonusers using propensity scores. The primary endpoint was metastasis-free survival (MFS), compared between groups using Kaplan-Meier analysis. A multivariable Cox proportional hazards model, adjusted for key covariates, was applied to the matched cohort to assess associations between statin use and survival outcomes.
Results: Of the 1,207 SPARTAN participants, 463 (38%) were baseline statin users; 456 users were propensity matched to 456 nonusers with balanced characteristics. Statin and nonstatin users were similarly distributed across treatment arms. While statin use was not associated with differences in metastasis-free survival (MFS) overall (P = 0.64), we observed a significant interaction by treatment arm (P = 0.018), with statin use linked to worse MFS in the placebo group (Hazard Ratio [HR] 1.40, 95% Confidence Interval [95% CI] 1.04-1.88). Statin use was also not associated with secondary endpoints overall, but again showed interaction for anticancer therapy-free survival, with harm in the placebo group (HR 1.32) and benefit in the apalutamide group (HR 0.79).
Conclusion: In this secondary analysis of the SPARTAN trial, statin use was not associated with improved survival outcomes overall. However, a significant interaction was observed, with statin use linked to worse metastasis-free survival in the placebo arm. These findings suggest a hypothesized interplay between statins and androgen receptor inhibition that warrants further prospective investigation.

