Statin use not associated with improved outcomes in patients treated with brachytherapy for prostate cancer

Purpose: To investigate the association between statin use and prostate cancer outcomes in intermediate- and high-risk patients treated with brachytherapy for prostate cancer.

Methods and materials: Between 1998 and 2010, 754 men with National Comprehensive Cancer Network intermediate- (n = 627) and high-risk (n = 127) prostate cancer were treated with prostate brachytherapy at our institution. Patients received either low-dose-rate or high-dose-rate brachytherapy as monotherapy or in combination with supplemental external beam radiotherapy. Two hundred eighty-five patients (37.8%) also received androgen-deprivation therapy. Two hundred seventy-three men (36.2%) were identified as taking statin medication before initiating radiation therapy. Prostate-specific antigen relapse-free survival (PSA-RFS), distant metastasis-free survival (DMFS), and overall survival were compared using log-rank tests. Associations of patient and treatment characteristics with outcomes were analyzed with univariate and multivariate regression. The median followup was 48 months.

Results: The 8-year PSA-RFS for intermediate-risk, high-risk, and all patients was 92.2%, 64.1%, and 87.7%, respectively. The 8-year DMFS was 97.1%, 82.9%, and 94.9%, respectively. The 8-year overall survival for the entire cohort was 86.6%. There were no significant differences between statin users and nonusers when stratified by risk group, nor when analyzed as a full cohort. On multivariate analysis, Gleason score 4 + 3 = 7 and >7 were significantly associated with worse PSA-RFS (p ≤ 0.003 and <0.001, respectively). Gleason score > 7 (p = 0.008) and the use of neoadjuvant androgen-deprivation therapy (p = 0.03) was associated with worse DMFS. Statin use did not significantly impact PSA-RFS or DMFS.

Conclusions: Pretreatment statin use is not associated with improved outcomes in intermediate- and high-risk patients undergoing prostate brachytherapy-based regimens for prostate cancer.