Is Chemical/Surgical Castration Necessary During Docetaxel Chemotherapy For Castration-Resistant Prostate Cancer?

e16530 Background: Docetaxel is the standard treatment for castration-resistant prostate cancer (CRPC). However, the role of chemical/surgical castration during docetaxel chemotherapy is unclear. The purpose of this study was to analyze the impact of castration during docetaxel chemotherapy. Methods: Data from 43 patients diagnosed with CRPC and treated at our institute with docetaxel chemotherapy, from January 2007 to September 2016, were analyzed retrospectively. They were divided into two groups according to the continuation of chemical castration during docetaxel chemotherapy: a continuation group and a discontinued group. Patients’ background data (age and serum prostate-specific antigen [PSA] level), PSA decline, progression-free survival, and overall survival were compared between the two groups. Results: The continuation group included 19 patients, and the discontinued group included 24 patients. Castration included surgical castration (15.8%), use of a luteinizing hormone-releasing hormone (LH-RH) agonist (68.4%), and use of an LH-RH antagonist (15.8%). There were no significant differences in patient age (73.5 years vs. 73.5 years; p = 0.878) and baseline serum PSA levels (14.25 ng/ml vs. 31.1 ng/ml, p = 0.745) between the two groups at the start of chemotherapy. PSA declines of ≥50% were observed in 7/14 patients and in 9/20 patients, respectively. There were no significant differences between the two groups with respect to the median progression-free survival (5.7 months vs. 9.9 months, p = 0.406) and overall survival. (52.1 months vs. 44.1 months, p = 0.776). Conclusions: Continuing chemical/surgical castration during docetaxel chemotherapy did not affect progression and prognosis of CRPC. Our results might suggest that chemical castration is not necessary during docetaxel chemotherapy.