2. Patients must have metastatic progressive androgen-independent prostate cancer. There must be radiographic evidence of disease that has continued to progress despite hormonal agents. Progression requires that a measurable lesion is expanding, new lesions have appeared, and/or that prostatic specific antigen (PSA) is continuing to rise on successive measurements. Patients on flutamide must have disease progression at least 4 weeks after withdrawal. Patients on bicalutamide or nilutamide must have progression at least 6 weeks after withdrawal.