DISEASE CHARACTERISTICS: Histologically proven prostate cancer limited to the prostate (including seminal vesicle and/or local lymph node involvement) with elevated PSA (greater than 2 ng/ml) following surgery or rising PSA following radiotherapy Negative bone scan and CT scan of abdomen and pelvis No PSA progression during chemotherapy, hormonal therapy (including steroids), or neoadjuvant or adjuvant androgen ablation therapy