DISEASE CHARACTERISTICS: Histologically proven, symptomatic prostate cancer Appearance or aggravation of clinical symptoms with progression of disease Bone pain OR Urethral compression OR 20% decrease in performance status Metastatic disease Local-regional or distant secondary tumors Documented radiologically or scintigraphically Hormone-refractory as defined by progression while on hormone treatment (simple castration or complete androgen blockage) Progressive disease No urethral or cervical stenosis Increase of greater than 25% prostatic volume on endorectal echography No documentation by PSA increase or imagery only Hormone castration verified by testosterone less than 0.5 ng/mL No history of CNS metastases