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Prostate Cancer
Volume 2017 (2017), Article ID 8560827, 8 pages
https://doi.org/10.1155/2017/8560827
Research Article

Efficacy of Abiraterone and Enzalutamide in Pre- and Postdocetaxel Castration-Resistant Prostate Cancer: A Trial-Level Meta-Analysis

1Department of Population and Quantitative Health Sciences, Case Western Reserve University School of Medicine, Cleveland, OH, USA
2University of Kentucky College of Medicine, Lexington, KY, USA
3Departments of Oncology and Urology, Johns Hopkins University School of Medicine, Baltimore, MD, USA

Correspondence should be addressed to Chun Li; ude.esac@197lxc

Received 10 August 2017; Accepted 26 October 2017; Published 21 November 2017

Academic Editor: William L. Dahut

Copyright © 2017 Mike Fang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We examined the comparative efficacies of first-line abiraterone and enzalutamide in pre- and postdocetaxel settings in castration-resistant prostate cancer (CRPC) through a trial level meta-analysis. A mixed method approach was applied to 19 unique studies containing 17 median overall survival (OS) estimates and 13 median radiographic progression-free survival (PFS) estimates. We employed a random-effects meta-analysis to compare efficacies of abiraterone and enzalutamide with respect to OS and PFS. In the predocetaxel setting, enzalutamide use was associated with an increase in median OS of 5.9 months (), hazard ratio (HR) = 0.81, and an increase in median PFS of 8.3 months (), HR = 0.47 compared to abiraterone. The advantage of enzalutamide improved after adjusting for baseline Gleason score to 19.5 months () and 14.6 months () in median OS and PFS, respectively. In the postdocetaxel setting, the advantage of enzalutamide use was nominally significant for median PFS (1.2 months without adjustment and 2.2 months and after adjustment); there was no significant difference in median OS between the two agents. The results from this comprehensive meta-analysis suggest a survival advantage with the use of first-line enzalutamide over abiraterone in CRPC and highlight the need for prospective clinical trials.