Special ArticlesReport From the International Society of Urological Pathology (ISUP) Consultation Conference on Molecular Pathology of Urogenital Cancers. I. Molecular Biomarkers in Prostate CancerLotan, Tamara L. MD*,†,‡; Tomlins, Scott A. MD, PhD§; Bismar, Tarek A. MD∥; Van der Kwast, Theodorus H. MD, PhD¶; Grignon, David MD#; Egevad, Lars MD**; Kristiansen, Glen MD††; Pritchard, Colin C. MD, PhD‡‡; Rubin, Mark A. MD§§; Bubendorf, Lukas MD∥∥Author Information Departments of *Pathology †Oncology ‡Urology, Johns Hopkins University, Baltimore, MD §Department of Pathology, Urology and Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI ∥Department of Pathology and Laboratory Medicine, University of Calgary Cumming School of Medicine and Alberta Public Labs, Calgary, AB ¶Laboratory Medicine Program, University Health Network, Toronto, ON, Canada #Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN **Department of Oncology and Pathology, Karolinska Institute, Solna, Sweden ††Department of Pathology, University Hospital Bonn, Bonn, Germany ‡‡Department of Laboratory Medicine, University of Washington, Seattle, WA §§Department for Biomedical Research, University of Bern and Bern Center for Precision Medicine, Bern ∥∥Institute of Pathology, University Hospital Basel, Basel, Switzerland T.L.L. has received research funding from Ventana/Roche and GenomeDx Biosciences. S.A.T. has served as a consultant for and received honoraria from Janssen, AbbVie, Sanofi, Almac Diagnostics, and Astellas/Medivation. S.A.T. has had sponsored research agreements with Astellas/Medivation and GenomeDX. S.A.T. is an equity holder in, a prior consultant for, and current employee of Strata Oncology. M.A.R. has received research support from Sanofi-Aventis, Millennium Pharma, Eli-Lilly and Janssen. M.A.R. has served as a consultant or received honoraria from ROCHE and Novartis. T.A.B. has received research funding from GenomeDX. L.B. has received research funding from Ventana/Roche. G.K. has received research funding from Astellas Pharma and has received honoraria from Astellas, Roche and Janssen. The remaining authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article. Correspondence: Tamara L. Lotan, MD, 1550 Orleans St., Baltimore, MD 21231 (e-mail: email@example.com). The American Journal of Surgical Pathology: July 2020 - Volume 44 - Issue 7 - p e15-e29 doi: 10.1097/PAS.0000000000001450 Buy Metrics Abstract The combined clinical and molecular heterogeneity of prostate cancer necessitates the use of prognostic, predictive, and diagnostic biomarkers to assist the clinician with treatment selection. The pathologist plays a critical role in guiding molecular biomarker testing in prostate cancer and requires a thorough knowledge of the current testing options. In the setting of clinically localized prostate cancer, prognostic biomarkers such as Ki-67 labeling, PTEN loss or mRNA-based genomic signatures can be useful to help determine whether definitive therapy is required. In the setting of advanced disease, predictive biomarkers, such as the presence of DNA repair deficiency mediated by BRCA2 loss or mismatch repair gene defects, may suggest the utility of poly-ADP ribosylase inhibition or immune checkpoint blockade. Finally, androgen receptor–related biomarkers or diagnostic biomarkers indicating the presence of small cell neuroendocrine prostate cancer may help guide the use of androgen receptor signaling inhibitors and chemotherapy. In this review, we examine the current evidence for several prognostic, predictive and diagnostic tissue-based molecular biomarkers in prostate cancer management. For each assay, we summarize a recent survey of the International Society of Urology Pathology (ISUP) members on current testing practices and include recommendations for testing that emerged from the ISUP Working Group on Molecular Pathology of Prostate Cancer and the 2019 Consultation Conference on Molecular Pathology of Urogenital Cancers. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.