MP53-02 SERUM TESTOSTERONE LEVEL IS A USEFUL BIOMARKER TO AID OPTIMAL TREATMENT SELECTION IN MEN WITH CASTRATION-RESISTANT PROSTATE CANCER

Abstract

You have accessJournal of UrologyProstate Cancer: Advanced (including Drug Therapy) III1 Apr 2017MP53-02 SERUM TESTOSTERONE LEVEL IS A USEFUL BIOMARKER TO AID OPTIMAL TREATMENT SELECTION IN MEN WITH CASTRATION-RESISTANT PROSTATE CANCER Kohei Hashimoto, Tetsuya Shindo, Hidetoshi Tabata, Toshiaki Tanaka, Jiro Hashimoto, Ryuta Inoue, Takashi Shimizu, Takashi Muranaka, Hiroshi Hotta, Atsushi Takahashi, Masahiro Yanase, and Naoya Masumori Kohei HashimotoKohei Hashimoto More articles by this author , Tetsuya ShindoTetsuya Shindo More articles by this author , Hidetoshi TabataHidetoshi Tabata More articles by this author , Toshiaki TanakaToshiaki Tanaka More articles by this author , Jiro HashimotoJiro Hashimoto More articles by this author , Ryuta InoueRyuta Inoue More articles by this author , Takashi ShimizuTakashi Shimizu More articles by this author , Takashi MuranakaTakashi Muranaka More articles by this author , Hiroshi HottaHiroshi Hotta More articles by this author , Atsushi TakahashiAtsushi Takahashi More articles by this author , Masahiro YanaseMasahiro Yanase More articles by this author , and Naoya MasumoriNaoya Masumori More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.1653AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Enzalutamide and abiraterone are frequently used for castration-resistant prostate cancer (CRPC), because of improved tolerability of them compared to taxanes. However, there are no predictive biomarkers to make a decision of how to best use abiraterone or enzalutamide. The aim of this study was to clarify the impact of serum testosterone in a decision-making of treatment selections (enzalutamide or abiraterone) for CRPC. METHODS We retrospectively evaluated consecutive CRPC patients treated at our institution and other satellite hospitals between 2013 and May 2016. A total of 115 patients received enzalutamide or abiraterone for CRPC and had serum testosterone measure at the initiation of the treatment were included in this study. The patients were divided into two groups by serum testosterone before enzalutamide or abiraterone: 54 in the testosterone <5 ng/dl group and 61 in the testosterone ≥5 ng/dl group. Prostate-specific antigen (PSA) response rates (defined as ≥50% PSA declines), PSA progression-free survival (PSA-PFS), and overall survival (OS) were compared between groups. RESULTS A total of 72 patients were treated with enzalutamide and 43 with abiraterone. In the testosterone <5 ng/dl group, the PSA response rates were significantly lower with enzalutamide than that with abiraterone (32% vs. 62%, p=0.033), whereas there was no difference in the testosterone ≥5 ng/dl group (81% vs. 93%, p=0.429). During the median follow-up period of 12 months, 68 men (59%) had PSA relapse. In the testosterone <5 ng/dl group, the median PSA-PFS was significantly lower with enzalutamide than that with abiraterone (2.8 months vs. 6.4 months, p=0.004) (Figure). Likewise, it was significantly lower with enzalutamide than that with abiraterone in the testosterone ≥5 ng/dl group (7.6 months vs. no available, p=0.004) (Figure). Multivariate analysis reveals that testosterone ≥5 ng/dl was an independent predictive factor for PSA-PFS (HR 3.1, p<0.001). However, there was no significant difference in the median OS according to the different testosterone groups. CONCLUSIONS This result suggests that serum testosterone level is a useful biomarker in a decision-making of treatment selections in the novel hormonal therapy for CRPC. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e713 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Kohei Hashimoto More articles by this author Tetsuya Shindo More articles by this author Hidetoshi Tabata More articles by this author Toshiaki Tanaka More articles by this author Jiro Hashimoto More articles by this author Ryuta Inoue More articles by this author Takashi Shimizu More articles by this author Takashi Muranaka More articles by this author Hiroshi Hotta More articles by this author Atsushi Takahashi More articles by this author Masahiro Yanase More articles by this author Naoya Masumori More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...