Note: Patients previously treated with an antiandrogen must have disease progression documented after antiandrogen withdrawal. Those who have not undergone orchiectomy must continue medical castration with a gonadotropin-releasing hormone analog. At least 4 weeks must have elapsed between the withdrawal of antiandrogens (6 weeks in the case of nilutamide or bicalutamide and four weeks in the case of flutamide or other secondary hormonal therapy) and enrollment, so as to avoid the possibility of confounding results of the response due to antiandrogen withdrawal.