GENITOURINARY SYSTEM: Edited by Arif HussainTargeting the androgen receptor and overcoming resistance in prostate cancerEinstein, David J.; Arai, Seiji; Balk, Steven P.Author Information Division of Medical Oncology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA Correspondence to David J. Einstein, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215, USA. Tel: +1 617 667 2100; e-mail: [email protected] Current Opinion in Oncology: May 2019 - Volume 31 - Issue 3 - p 175-182 doi: 10.1097/CCO.0000000000000520 Buy Metrics Abstract Purpose of review Prostate cancer (PCa) is diagnosed in one out of every nine men and is the second leading cause of cancer death among men. Although therapies targeting the androgen receptor (AR) are highly effective, development of resistance is universal and remains a major therapeutic challenge. Nonetheless, signaling via AR is frequently maintained despite standard androgen-signaling inhibition. We review the current understanding of mechanisms of resistance as well as therapeutic approaches to improving treatment of PCa via targeting of the AR. Recent findings Resistance to AR-targeting therapies may be mediated by several mechanisms, including amplification, mutation, and alternative splicing of AR; intratumoral androgen synthesis; activation of alternative signaling pathways; and in a minority of cases, emergence of AR-independent phenotypes. Recent trials demonstrate that intensification of androgen blockade in metastatic castration-sensitive PCa can significantly improve survival. Similar strategies are being explored in earlier disease states. In addition, several other cellular signaling pathways have been identified as mechanisms of resistance, offering opportunities for cotargeted therapy. Finally, immune-based approaches are in development to complement AR-targeted therapies. Summary Targeting the AR remains a critical focus in the treatment of PCa. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.