Combined androgen blockade in the management of advanced prostate cancer: A sensible or ostensible approach

BACKGROUND: To compare the efficacy of orchiectomy alone and orchiectomy plus flutamide in treating patients with advanced carcinoma prostate. MATERIALS AND METHODS: The study was initiated on 1 July 1997 and closed after enrolling 100 patients on 30 June 2000. Patients were prospectively randomized to orchiectomy alone (O) and orchiectomy plus flutamide (OF). A complete response (CR) was defined as the normalization of bone scans and serum prostate-specific antigen (PSA) levels returning to normal (< 4 ng/mL). A partial response (PR) was defined as a 50% reduction in metastasis mass compared to the initial study or a decrease in the PSA level of 50% of the initial value. Progressive disease (PD) was defined as the development of any new hot spot on bone scan or any increase in previously existing PSA level by 25%. RESULTS: A total of 100 patients were entered in the study. The maximum percentage change in PSA levels in both groups was found in the first 3 months after orchiectomy, that is, 95% and 97% for the O and OF groups, respectively. In more than 80% of the patients this decrease in PSA was maintained for 3 years. The mean percentage change at 3 years in the O and OF groups was 70% and 75% (P = 0.95), respectively, and the overall response rate (CR + PR) was 88.50% and 86.53% in the two groups, respectively (P = 0.85). The follow-up period ranged between 3 and 5 years (mean, 3.5 years). The mean time to progression was 27 and 29 months in the O and OF groups, respectively. The overall survival rate at 3 and 5 years in two treatment groups was 45.83% and 48.07%, 20.83% and 23.07% in the O and OF groups, respectively (P = 0.75). CONCLUSIONS: Maximum percentage decrease in PSA is seen within the first 3 months of therapy. Orchiectomy alone is as effective as combination therapy in decreasing serum PSA. Overall survival at 3 and 5 years in the orchiectomy only group was as good as that of combination therapy. These data suggest that the routine addition of flutamide to orchiectomy is not advisable.