DISEASE CHARACTERISTICS: Histologically documented androgen dependent or independent prostate cancer Progressive disease on primary hormonal treatment (e.g., orchiectomy, estrogen therapy, gonadotropin releasing hormone analog with or without an antiandrogen) New osseous lesions by bone scan OR 25% increase in bidimensionally measurable soft tissue disease or appearance of new sites of disease by MRI or CT scan If initial hormonal treatment was a combined androgen blockade approach, must show progression off of the antiandrogen Minimum of 3 rising PSA values from baseline obtained 1 week or more apart OR 2 rising PSA values obtained 2 or more weeks apart PSA at least 4 ng/mL Testosterone no greater than 30 ng/mL No active CNS or epidural tumor