Radiation Therapy With or Without Androgen-Deprivation Therapy in Treating Patients With Prostate Cancer

RATIONALE: Radiation therapy uses high-energy x-rays and other types of radiation to kill tumor cells and shrink tumors. Androgens can cause the growth of prostate cancer cells. Androgen-deprivation therapy may lessen the amount of androgens made by the body. It is not yet known whether radiation therapy is more effective with or without androgen-deprivation therapy in treating patients with prostate cancer. PURPOSE: This randomized phase III trial is studying radiation therapy to see how well it works compared with radiation therapy given together with androgen-deprivation therapy in treating patients with prostate cancer.

OBJECTIVES: Primary * Demonstrate an overall survival (OS) advantage in patients with intermediate-risk prostate cancer treated with dose-escalated radiotherapy (RT) with versus without short-term androgen-deprivation therapy (ADT). Secondary * Determine whether the addition of ADT to dose-escalated RT versus RT alone improves clinical failures, biochemical failure by the "nadir +2", freedom from failure, rate of salvage ADT, and prostate cancer-specific mortality in these patients. * Estimate the magnitude of benefit of ADT with respect to OS in patients treated with different RT modalities (i.e., external-beam radiation therapy alone vs low-dose rate brachytherapy boost vs high-dose rate brachytherapy boost). * Compare acute and late treatment adverse events of these regimens and correlate these events with the presence or absence of pre-existing comorbidity as documented by the Adult Comorbidity Evaluation 27 assessment. OUTLINE: This is a multicenter, dose-escalation study of radiotherapy. Patients are stratified according to number of risk factors (1 vs 2-3), comorbidity (ACE-27 grade ≥ 2 vs \< 2), and radiotherapy (RT) modality (dose-escalated external-beam RT \[EBRT\] vs EBRT and low-dose rate brachytherapy boost vs EBRT and high-dose rate brachytherapy boost). Patients are randomized to 1 of 2 treatment arms. After completion of study therapy, patients are followed up periodically.