Radiation Therapy Combined With Hormone Therapy for Prostate Cancer

Standard-dose radiation therapy has limited capacity to cure bulky and locally advanced prostate cancer. Multiple randomized trials have shown a clinical benefit to adding androgen suppression therapy to external-beam radiation therapy in several subsets of prostate cancer. These studies have made combining hormonal therapy with radiation therapy the standard of care for men with locally advanced (T3-4) and unfavorable prostate cancers (Gleason score ≥8 and/or prostate-specific antigen >20 ng/mL). The clinical impact of hormonal therapy has been seen in biochemical control, local control, distant metastases, disease-specific survival, and overall survival. If hormonal therapy is to be combined with radiation, it should be initiated before the start of radiation and continued during the radiation course rather than used only in the adjuvant setting. Typically, shorter-term hormone therapy is defined as regimens of 4 to 6 months, with longer-term hormone therapy describing durations beyond 24 months. Historically, longer-term hormone therapy was thought to have a more profound systemic effect; however, with the emerging use of hormonal therapy for less-advanced disease, the overall impact of shorter-course hormone therapy is being seen. This review will summarize trials using hormonal therapy and radiation with an emphasis on phase III studies and describe the more recent integration of hormone therapy with radiation for prostate cancer.