Radiation Therapy in Treating Patients With Stage II Prostate Cancer

OBJECTIVES: * Compare the overall survival of patients with stage II adenocarcinoma of the prostate treated with high- vs standard-dose three-dimensional conformal or intensity-modulated radiotherapy. * Compare the freedom from prostate-specific antigen failure, disease-specific survival, local progression, and distant metastases in patients treated with these regimens. * Compare the probability of tumor control and normal tissue complications in patients treated with these regimens. * Compare the incidence of grade 2 or greater genitourinary and gastrointestinal acute and late toxicity in patients treated with these regimens. * Compare the quality of life, including sexual function, of patients treated with these regimens. * Correlate histopathologic or tumor-specific cytogenetic or chromosomal markers with cancer control outcomes in patients treated with these regimens. OUTLINE: This is a randomized, multicenter study. Patients are stratified according to Gleason score and prostate-specific antigen (PSA) level (Gleason score 2-6, PSA ≥10 mg/mL but \< 20 ng/mL vs Gleason score 7, PSA \< 15 ng/mL) and radiation modality (three-dimensional conformal radiotherapy \[3D-CRT\] vs intensity-modulated radiotherapy \[IMRT\]). Patients are randomized to 1 of 2 treatment arms. * Arm I: Patients undergo standard-dose 3D-CRT or IMRT once daily, 5 days a week, for 7.8 weeks (39 treatment days). * Arm II: Patients undergo high-dose 3D-CRT or IMRT once daily, 5 days a week, for 8.8 weeks (44 treatment days). Quality of life (QOL) is assessed initially at baseline. After completion of radiotherapy, QOL is assessed every 3 months for 1 year and then every 6 months for 4 years. Patients are followed every 3 months for 2 years, every 6 months for 3 years, and then annually thereafter. PROJECTED ACCRUAL: A total of 1,520 patients (760 per treatment arm) will be accrued for this study within 5 years.