EZH2 overexpression as a biomarker of poor prognosis in prostate cancer

A number of studies have investigated the prognostic role of enhancer of zeste homolog 2 (EZH2) expression for patients with prostate cancer (PCa), however, the results were controversial. The current study was aimed to comprehensively explore the association between EZH2 and clinical outcomes of PCa by using meta-analysis. The electronic databases of Pubmed, Embase and Web of Science were searched. Combined hazard ratio (HR) and 95% confidence interval (CI) were computed using Stata 12.0 software. Seven studies with 1120 patients were included. The results demonstrated that high EZH2 expression was associated with poor recurrence-free survival (RFS) in PCa (HR=1.87, 95% CI=1.57-2.23, P<0.001). Subgroup analysis showed that EZH2 overexpression had enhanced prognostic significance for patients in Western countries (HR=2.22, 95% CI=1.61-3.05, P<0.001). In addition, elevated EZH2 expression also predicted poor RFS in patients receiving radical prostatectomy (RP) (HR=1.85, 95% CI: 1.55-2.21, P<0.001) and when immunohistochemistry staining (IHC) was used to detect EZH2 (HR=1.87, 95% CI: 1.55-2.24, P<0.001). In conclusion, EZH2 overexpression was distinctly correlated with poor patient RFS in PCa. EZH2 could serve as a prognostic biomarker in PCa patients.