Assessing the Optimum Use of Androgen-Deprivation Therapy in High-Risk Prostate Cancer Patients Undergoing External Beam Radiation Therapy

The optimum use of androgen deprivation therapy (ADT) in high-risk prostate cancer patients has not been defined in the setting of dose-escalated external beam radiation therapy. A retrospective analysis of 1,290 patients with high-risk prostate cancer from June 1987 through March 2010 treated with external beam radiation therapy was performed. Median follow-up was 7.2 years, and 797 patients received ADT, with 384 patients experiencing a biochemical failure and 145 with distant metastasis. ADT was associated with lower risk of biochemical failure and distant metastasis than no ADT after adjusting for age, prostate-specific antigen (PSA), Gleason score, year of diagnosis, tumor stage, and radiation dose. ADT was associated with a greater reduction in biochemical failure in the low-dose radiation group than in the high-dose group. Patients with >24 months of ADT had a lower risk of PSA failures than those with 24 months of ADT in all patients who received ADT.