Effect of enhancer of zeste homolog 2 mutations on the prognosis of patients with myelodysplastic syndrome: A meta-analysis

BACKGROUND: Gene mutations with important prognostic roles have been identified in patients with myelodysplastic syndrome (MDS). Overall, it is not yet fully clear whether enhancer of zeste homolog 2 (EZH2) is affected and contributes to the disease in MDS patients. Thus, we performed a meta-analysis to investigate the effects of EZH2 mutations on the prognosis of patients with MDS. METHODS: We searched English-language databases (PubMed, Embase, and Cochrane Library) for studies published on the effects of EZH2 mutations in MDS patients. The study had to include at least 1 of the following indices as therapeutic evaluation data: overall survival (OS), transformation time to leukemia, and International Prognostic Scoring System risk. Revman, version 5.2 software was used for all statistical processing. We calculated the risk ratio and the 95% confidence interval (CI) of continuous variables, and determined the hazard ratio and 95% CI of time-to-event data. RESULTS: We included 5 studies with a total enrolment of 994 patients. There was a significant adverse effect on OS in the EZH2-mutation group compared to the unmutated group (hazard ratio = 2.47, 95% CI: 1.37–4.47, P < .00001), while the heterogeneity was relatively high (I(2) = 68%). There was no significant correlation between EZH2 mutations and IPSS risk (low/int-1 vs int-2/high) (odds ratio: 0.69, 95% CI: 0.14–3.39, P = .65), with significant heterogeneity (I(2) = 78%). The analysis did not show significant publication bias in the studies. CONCLUSION: This meta-analysis indicated an adverse effect of EZH2 mutations with regard to OS in patients with MDS. However, larger cohort trials are still needed to better understand the prognostic impacts of EZH2 mutations on MDS patients.