Predictive Factors for Premature Discontinuation of Docetaxel-Based Systemic Chemotherapy in Men With Castration-Resistant Prostate Cancer

PURPOSE: The objective was to determine predictive factors for premature discontinuation of docetaxel-based systemic chemotherapy in men with castration-resistant prostate cancer (CRPC). MATERIALS AND METHODS: We retrospectively reviewed the medical records of men who were treated with docetaxel-based systemic chemotherapy for CRPC in a single institution between May 2005 and April 2010. After being screened, 30 patients fit the eligibility criteria for inclusion in this study. Group 1 included 12 patients who were treated with five or fewer cycles of docetaxel chemotherapy for CRPC, and group 2 included 18 patients who were treated with six or more cycles of docetaxel chemotherapy for CRPC. The treatment consisted of 5 mg prednisolone twice daily and 75 mg/m(2) docetaxel once every 3 weeks. RESULTS: The median age was 72 years, and the median Eastern Cooperative Oncology Group (ECOG) performance status was 0. The median baseline prostate-specific antigen (PSA) level was 33.8 ng/mL. The median cycle of docetaxel-based chemotherapy was 5.8. Of 30 patients, 13 patients (48.2%) had a decline in PSA of >50% from baseline; 3 of 22 patients (13.6%) with measurable disease had achieved partial response on imaging. No differences in age, ECOG performance status, hemoglobin, serum creatinine, or PSA response were observed between the two groups. Body mass index was significantly lower (p=0.034) in group 1 (21.8 kg/m(2)) than in group 2 (23.6 kg/m(2)). Group 1 included more patients with prior systemic chemotherapy (p=0.039), and group 1 had a shorter overall survival rate (p=0.039). CONCLUSIONS: Premature discontinuation of docetaxel-based systemic chemotherapy is associated with lower body mass index and prior systemic chemotherapy. Premature discontinuation of docetaxel-based chemotherapy is associated with a shorter overall survival rate.