Outcome of Combination Chemotherapy with Docetaxel, Estramustine Phosphate, and Carboplatin after Docetaxel and Prednisolone Therapy in Patients with Metastatic Castration-Resistant Prostate Cancer

Abstract

We retrospectively reviewed the outcome of docetaxel, EMP, and carboplatin (DEC) as second-line chemotherapy in castration-resistant prostate cancer (CRPC) patients previously treated with docetaxel-prednisolone (DP). Nineteen patients pretreated with DP received a DEC regimen which consisted of a 28-day cycle of docetaxel [60 mg/m2 intravenously (IV) on day 1)], carboplatin (IV to an area under the curve of 5 on day 1), and EMP (560 mg orally daily). The DEC therapy was continued intermittently after two consecutive courses. End points were DEC effect on prostate-specific antigen (PSA), radiographic response, progression-free survival (PFS), and overall survival (OS). All patients received DP before DEC administration with a median of 6 cycles (range, 1 - 12). Mean follow-up duration was 19.0 months after starting DEC therapy; median total number of the therapy cycles was 2 (range, 1 - 11). Thirteen patients (68.4%) showed a PSA decrease; 6 (31.6%) showed a decrease in the PSA level of ≥50%, including 4 with no PSA response to DP. Grade 3/4 neutropenia and febrile neutropenia were observed in 13 (68.4%) and 2 (10.5%) patients, respectively. The median PFS following DEC was 3.7 months. The median OS was 18.0 months. In univariate analyses, patients with ≤12 months from CRPC to DEC had shorter PFS and OS, whereas PSA response to DP was not associated with PFS or OS in CRPC patients treated with DEC after DP. In conclusion, DEC retains some clinical benefits for CRPC patients pretreated with DP, even in patients without any response to DP. Therefore, they may be an effective and feasible treatment option for CRPC patients after first-line docetaxel therapy, particularly for those deemed unfit for novel endocrine and chemotherapeutic drugs.