title: Prognostic significance of EZH2 expression in patients with digestive cancers: a meta-analysis.
abstract: BACKGROUND
  Enhancer of zeste 2 (EZH2), a key component of polycomb repressive complex 2 (PRC2), was of great importance in human cancer pathogenesis. Various studies examined the relationship between EZH2 overexpression with the clinical outcome in patients with digestive cancers, but yielded inconsistent results.
  
  
  METHODS
  Electronic databases updated to January 2015 were searched to find relevant studies. A meta-analysis was conducted with eligible studies which quantitatively evaluated the relationship between EZH2 overexpression and survival of patients with digestive cancers. Survival data were aggregated and quantitatively analyzed.
  
  
  RESULTS
  We performed a meta-analysis of 10 studies (n = 1,461 patients) that evaluated the correlation between EZH2 overexpression and survival in patients with digestive cancers. Combined hazard ratios suggested that EZH2 overexpression was associated with poor prognosis of overall survival (HR = 1.54, 95% CI: 1.27-1.81) in patients with esophageal cancer. In the stratified analysis, no significantly risks were found among gastric cancer (HR = 0.66, 95% CI: 0.16-1.15) and colorectal cancer (HR = 0.91, 0.63-1.19), indicating EZH2 was not an indicator of poor prognosis in gastric cancer or colorectal cancer.
  
  
  CONCLUSIONS
  EZH2 overexpression indicates a poor prognosis for patients with esophageal cancer, but not among gastric cancer or colorectal cancer.
authors.affiliation: Department of General Surgery, The 81st hospital of P.L.A., P.L.A. cancer center Nanjing, P. R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of General Surgery, The 81st hospital of P.L.A., P.L.A. cancer center Nanjing, P. R. China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of General Surgery, The 81st hospital of P.L.A., P.L.A. cancer center Nanjing, P. R. China.
authors.forename: Guangquan
authors.initials: G
authors.lastname: Zong
authors.affiliation: Department of General Surgery, The 81st hospital of P.L.A., P.L.A. cancer center Nanjing, P. R. China.
authors.forename: Renmin
authors.initials: R
authors.lastname: Liu
authors.affiliation: Department of General Surgery, The 81st hospital of P.L.A., P.L.A. cancer center Nanjing, P. R. China.
authors.forename: Yufei
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of General Surgery, The 81st hospital of P.L.A., P.L.A. cancer center Nanjing, P. R. China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Luan
authors.affiliation: Department of General Surgery, The 81st hospital of P.L.A., P.L.A. cancer center Nanjing, P. R. China.
authors.forename: Lin
authors.initials: L
authors.lastname: Xu
authors.affiliation: Department of General Surgery, The 81st hospital of P.L.A., P.L.A. cancer center Nanjing, P. R. China.
authors.forename: Ji
authors.initials: J
authors.lastname: Xuan
keywords: Enhancer of zeste homolog 2; colorectal cancer; esophageal cancer; gastric cancer; meta-analysis; prognosis