Orchiectomy and nilutamide or placebo as treatment of metastatic prostatic cancer in a multinational double-blind randomized trial.

The efficacy and tolerance of the nonsteroidal antiandrogen nilutamide in the treatment of prostatic cancer were studied in a large double-blind clinical trial initiated in 1986. Patients with metastatic prostatic cancer without prior endocrine manipulation underwent orchiectomy and were randomized to 1 of 2 groups receiving nilutamide (225 patients) or placebo (232). Nilutamide and placebo were evaluated for efficacy in 207 and 216 patients, respectively. Progression-free survival was significantly longer in the nilutamide group (median time to progression 20.8 months on nilutamide and 14.9 months on placebo, p = 0.005). Median time to death from prostatic cancer was 30.0 months in the placebo group and 37 months in the nilutamide group. Objective regressions were higher in the nilutamide group (41%) than in the placebo group (24%). Significant differences in favor of the nilutamide group were found at several intervals for bone pain, prostatic acid phosphatase, prostate specific antigen, alkaline phosphatase and bone scan isotope uptake. Nilutamide and orchiectomy constitute a more effective treatment for metastatic prostatic cancer than orchiectomy alone, and the adverse effects of nilutamide, usually minor, are outweighed by the significant improvements in most disease measures and progression-free survival.