Long-term efficacy and safety of nilutamide plus castration in advanced prostate cancer, and the significance of early prostate specific antigen normalization

Purpose: We studied the long-term efficacy and tolerability of nilutamide, a nonsteroidal antiandrogen, combined with orchiectomy in patients with advanced prostate cancer. Materials and Methods: A large double-blind trial was done on 457 patients randomized to receive nilutamide or placebo after orchiectomy. Results: At 8.5 years of followup significant benefits were found for progression and survival in favor of patients receiving nilutamide and orchiectomy. In addition, normalized prostate specific antigen levels at 3 months from the start of therapy were predictive of good long-term outcome. Moreover, combined androgen blockade with nilutamide increased the chance of patients having normal prostate specific antigen levels at 3 months. Nilutamide was well tolerated in the long term with no increase in the incidence of drug specific adverse events. Conclusions: With long-term followup of patients with advanced prostate cancer, the combination of nilutamide and orchiectomy has significant benefits in interval to progression and improved survival compared to orchiectomy and placebo.