Abiraterone versus bicalutamide in combination with gonadotropin releasing hormone antagonist therapy for high risk metastatic hormone sensitive prostate cancer.

Objectives: To compare the efficacy of abiraterone with that of bicalutamide in combination with gonadotropin-releasing hormone antagonist treatment for high risk metastatic hormone-sensitive prostate cancer patients. Methods: One hundred and forty-nine patients with high risk metastatic hormone-sensitive prostate cancer at our hospital and affiliated hospitals between December 2013 and July 2020 were retrospectively identified. Fifty patients were administered abiraterone (1000mg/day) plus prednisolone (5mg/day) with gonadotropin-releasing hormone antagonist (degarelix) (group A) and 99 patients were administered bicalutamide (80mg/day) with gonadotropin-releasing hormone antagonist (group B). Results: PSA- progression-free survival of group A was significantly longer than that of group B. Abiraterone therapy and Gleason score were significant independent factors for PSA-progression-free survival. By propensity score matching, total 56 matched patients were obtained. PSA-PFS (p<0.001) and OS (p=0.0071) of high risk mHNPC patients were significantly longer in abiraterone group of matched patients. Abiraterone therapy and Gleason score were still shown to be significant independent factors for PSA-PFS in matched patients. Conclusions: PSA-progression-free survival and overall survival in patients who were treated with abiraterone in combination with gonadotropin releasing hormone antagonist were significantly better than those of bicalutamide.