PRIOR CONCURRENT THERAPY: Biologic therapy: Prior gene therapy and antibody therapy allowed Chemotherapy: No prior cytostatic chemotherapy, including estramustine Endocrine therapy: See Disease Characteristics At least 1 month since prior antiandrogen therapy (e.g., flutamide or bicalutamide) without tumor response OR Concurrent antiandrogen therapy allowed if clinically unacceptable to discontinue use If disease progressed while receiving hormonal agents (e.g., goserelin, leuprolide, diethylstilbestrol), therapy must continue during study Radiotherapy: At least 4 weeks since prior radiotherapy No prior radiotherapy to lesions to be evaluated No concurrent radiotherapy to more than one area Surgery: See Disease Characteristics Other: Prior noncytostatic therapy allowed At least 1 month since prior investigational drugs