Adjuvant Radiation Therapy Plus Hormone Therapy Compared With Radiation Therapy Alone in Treating Patients With Stage II or Stage III Prostate Cancer

DISEASE CHARACTERISTICS: Histologically confirmed prostate cancer T2-3, N0, M0 No metastatic disease High-risk for PSA relapse as defined by Gleason score 7 or higher and ≥ 1 of the following OR Gleason score < 7 and ≥ 2 of the following: Preoperative PSA > 10 ng/mL Positive surgical margins Seminal vesicle invasion Preoperative PSA ≤ 40.0 ng/mL Postoperative PSA ≤ 0.2 ng/mL Negative lymph node status by lymph node sampling or dissection If lymph node status is unknown, must have < 5% risk of involvement by Roach formula PATIENT CHARACTERISTICS: Age: Not specified Performance status: Zubrod 0-1 Life expectancy: Not specified Hematopoietic: WBC ≥ 3,000/mm^3 Platelet count ≥ 130,000/mm^3 Hemoglobin ≥ 11.4 g/dL Hepatic: ALT ≤ 3 times normal Renal: Creatinine ≤ 2.5 mg/dL Other: No other prior or concurrent invasive malignancy within the past 5 years except superficial nonmelanoma skin cancer No other major medical or psychiatric illness that would preclude study compliance PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: At least 5 years since prior chemotherapy Endocrine therapy: At least 60 days since prior finasteride At least 90 days since prior testosterone Prior pharmacologic androgen ablation for prostate cancer allowed if initiated within the past 10 months (must switch to study ablation therapy OR discontinue therapy if randomized to receive radiotherapy only) Radiotherapy: No prior radiotherapy to the pelvis No concurrent intensity-modulated radiotherapy Surgery: No prior orchiectomy