DISEASE CHARACTERISTICS: Histologically or cytologically proven carcinoma of the prostate that has relapsed subsequent to chemical or surgical castration and/or antiandrogen therapy Painful, unirradiated osseous metastasis required Documentation by bone scan and x-ray required Number and extent of metastases determined according to Soloway and fitting grades 1-3 Prior hormonal therapy must have lasted at least 3 months and must be continued until completion of this study No imminent paraplegia related to metastases No uncorrectable urinary incontinence