Treating the primary in metastatic prostate cancer: where do we stand?
Purpose of review Traditionally, local treatment was reserved for palliative control of symptoms in men with metastatic prostate cancer. In the past few years there have been many advances in the systemic options available. The aim of this review is to explore the evidence in support of treating the primary tumor despite the presence of metastatic disease. Recent findings There is a wealth of retrospective studies demonstrating advantages of local treatment [radical prostatectomy or radiation therapy (RT)] in metastatic disease. As these studies are prone to bias, treatment of the primary in the metastatic setting has not been adopted. However, two recent prospective randomized trials (HORRAD and STAMPEDE) have addressed the role of RT to the prostate in metastatic disease. The STAMPEDE sub-group analysis of low-volume metastatic disease demonstrated a survival advantage in favor of the RT arm (hazard ratio 0.68; 95% CI 0.52–0.90). The HORRAD trial showed a similar but nonsignificant trend towards RT (hazard ratio 0.68; 95% CI 0.42–1.10). As a result, the 2019 European Association of Urology and National Comprehensive Cancer Network guidelines now include RT to the prostate as an option in the setting of low-volume metastatic disease. Summary Although systemic treatment remains standard of care for men with metastatic prostate cancer, there is recent compelling evidence from two prospective randomized trials supporting treatment of the prostate in oligometastatic disease. Correspondence to Robert J. Hamilton, MD, MPH, FRCSC, Staff Urologist, Associate Professor, Division of Urology, Department of Surgery, Princess Margaret Cancer Centre, 600 University Avenue, Toronto, ON, Canada M5G 1X5. Tel: +1 416 946 2909; fax: +1 416 946 6590; e-mail: rob.hamilton@uhn.ca Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.