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

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.