Prednisone Active Not Recruiting Phase 2 Trials for Stage IV Prostate Adenocarcinoma AJCC v7 / Stage IV Prostate Cancer AJCC v7 / Stage III Prostate Cancer / Stage III Prostate Cancer AJCC v7 / Stage III Prostate Adenocarcinoma / Stage III Prostate Adenocarcinoma AJCC v7 / Stage IV Prostate Cancer / Stage IV Prostate Adenocarcinoma Treatment