Clinicopathological significance and prognostic role of EZH2 expression in non-small cell lung cancer.

OBJECTIVE: The aim of this study was to investigate the clinicopathological characteristics and prognostic role of enhancer of zeste homologue 2 (EZH2) expression in non-small cell lung cancer (NSCLC).

METHODS: The correlation between EZH2 expression and the clinicopathological characteristics, including sex, smoking history, tumor differentiation, histologic type, tumor stage, and lymph node metastasis, was evaluated through a meta-analysis. In addition, the prognostic value of EZH2 expression was elucidated. This study included 1,932 patients with NSCLC from 11 eligible studies.

RESULTS: The overall rate of EZH2 expression was 0.548 [95% confidence interval (CI) 0.491-0.604]. There were significant correlations between EZH2 expression and male sex and smoking history. The expression rate of EZH2 was significantly lower in adenocarcinoma than in other histologic types. Furthermore, EZH2 expression rates were higher in NSCLC with moderately and poorly differentiation and nodal disease than in well-differentiated NSCLC without nodal disease. There was a significant correlation between EZH2 expression and worse overall and disease-free survival [hazard ratio (HR) 1.938, 95% CI 1.617-2.323 and HR 1.713, 95% CI 1.366-2.149, respectively]. Subgroup analysis revealed no significant difference for the prognostic effect of EZH2 expression between histologic types or detection methods.

CONCLUSION: Our data collectively suggest that EZH2 expression is significantly correlated with aggressive tumor behavior and poor prognosis in NSCLC.