Value of Enhancer of Zeste Homolog 2 (EZH2) for Determining Prognosis in Colon Cancer

Introduction: It has been reported that Enhancer of Zeste Homolog 2 ( EZH2) enhancer is expressed in Colorectal Cancer (CRC), but there are only limited findings of its overexpression with prognosis in CRC. Aim: To investigate the association between EZH2 expression and clinicopathologic variables and outcome in CRC. Materials and Methods: This retrospective study retrieved the archived histological samples for immunohistochemistry evaluation of EZH2 and PCR analysis of KRAS from patients with CRC who were followed-up between April 2009 to June 2019. Kaplan-Meier methods were used for Overall Survival (OS) and Disease-Free Survival (DFS). Cox proportional hazard model and time dependent Cox model were used to evaluating association of clinicopathologic factors with OS and DFS. Results: Hundred patients with CRC were included with mean age and range 57.39 +/- 13.52 years and 21-83 years respectively. There were no significant association between OS (log-rank p-value=0.50) and DFS ( log-rank p-value=0.74) with EZH2 expression. Third quartile of OS was 30.7 days and for DFS was 107.83 days. According to the result of multivariate cox regression after adjusting for confounding variables, there was no significant association between EZH2 and OS (HR=1.53, 95% CI=0.63-3.72, p=0.35). Also, a borderline association was observed between EZH2 and DFS (HR=11.08, 95% CI=1.02-119.72, p=0.05). There were no significant associations between the DFS, OS and other clinicopathologic parameters except for the stage, respectively (HR=3.51, 95% CI=1.71-7.20, p=0.001) (HR=3.55, 95% CI=1.7-17.35, p=0.001). Conclusion: The expression of EZH2 in patients with CRC was not associated with clinical features, and does not appear to be associated with OS or DFS. EZH2 is an attractive target in cancer and much more research is clearly warranted.