Treatment of the primary tumor in metastatic prostate cancer

The cornerstone of treatment for metastatic prostate cancer patients has been conventional androgen deprivation therapy, with additional systemic therapy initiated only after castration resistance, and local therapy reserved for palliation. Compelling results from modern trials challenge this paradigm, arguing for initiating escalated hormone therapy and/or chemotherapy during the castration-sensitive disease state for many patients. Furthermore, modern radiotherapy techniques allow for local control of disease with low risk of toxicity. Finally, new PET probes with enhanced sensitivity and accuracy are likely to become a part of routine staging and will lead to an increased incidence of patients with metastatic disease at presentation, with a shift toward identification of patients with limited metastatic disease. As such, the landscape is primed for investigations aimed to explore the role of primary tumor therapy for patients with metastatic prostate cancer. We review the existing data evaluating primary tumor therapy for patients with metastatic prostate cancer and describe ongoing clinical trials testing the hypothesis that primary tumor therapy may benefit patients with metastatic prostate cancer.