No Effect of Statins on Biochemical Outcomes After Radiotherapy for Localized Prostate Cancer

ObjectivesTo examine the effect of concurrent statin use during definitive radiotherapy (RT) on the biochemical outcomes for localized prostate cancer.MethodsA total of 968 patients treated with RT had information about medication use available. Of these, 23% had been taking using statins during RT. Progression-free survival (PFS) was determined by a biochemical failure definition of prostate-specific antigen nadir plus 2 ng/mL, clinical failure, start of androgen deprivation therapy, or death.ResultsThe mean patient age was 68 years. The median radiation dose was 76 Gy. Of the patients, 29% underwent androgen deprivation therapy. The 5-year overall survival rate was 83%. The median PFS time was 7.8 years versus 6.4 years, and the 5-year PFS rate was 70% versus 59% in favor of the statin users (P = 0.03). The analysis by risk group demonstrated no significant statin effect in any of the three risk strata. Stratification by hydrophilic versus hydrophobic statin agents revealed similar results. Multivariate analysis revealed that T stage (P <0.0001), pretreatment prostate-specific antigen level (P <0.0001), and Gleason score (P = 0.0026) were significant predictors of PFS; however, statin use (P = 0.48), androgen deprivation therapy (P = 0.95), pelvic RT (P = 0.96), radiation dose (P = 0.13), age (P = 0.19), and year of treatment (P = 0.07) were not.ConclusionsStatin use did not affect PFS after adjusting for differences in treatment year and multiple prognostic factors. However, T stage, baseline prostate-specific antigen level, and Gleason score were critical determinants of prostate-specific antigen failure. These results did not differ when hydrophilic pravastatin was excluded.