Prognostic significance of the EVI1 gene expression in patients with acute myeloid leukemia: a meta-analysis

Ecotropic virus integration site-1 (EVI1) is frequently expressed in patients with acute myeloid leukemia (AML). Many studies have reported the potential poor prognostic impact of EVI1 higher expression (EVI1(H)) in the AML patients; however, the conclusions previously reported have not been fully assessed and are still controversial. Therefore, we performed a meta-analysis to evaluate the prognostic significance of EVI1(H) in patients with AML. The primary endpoint was overall survival (OS), and the event-free survival (EFS) was selected as the secondary endpoint. We extracted the hazard ratio (HR) and their 95% confidence interval (CI) for the OS and EFS from the multivariate COX proportional hazard models. A total of 4767 AML patients from 11 studies up to 23 February 2019 were subjected to our meta-analysis. Pooled HRs suggested that EVI1(H) had an adverse impact on OS (HR=1.52, 95%CI 1.24-1.86) and EFS (HR=1.41, 95%CI 1.14-1.74) in AML patients. EVI1(H) was also associated with a shorter OS (HR=1.73, 95%CI 1.43-2.11) and EFS (HR=1.17, 95%CI 1.05-1.31) in AML patients with the intermediate cytogenetic risk (ICR) according to the National Comprehensive Cancer Network (NCCN), European leukemia network (ELN), or International System for Human Cytogenetic Nomenclature (ISCN). Furthermore, EVI1(H) appeared to be a poor prognosis indicator in patients with normal cytogenetics (NC) (HR for OS:2.01, 95%CI 1.32-3.05; HR for EFS 1.54, 95%CI 1.09-2.17) and young patients (HR for OS 1.30, 95%CI 1.09-1.55), respectively. This meta-analysis indicates EVI1(H) has an independent and significantly adverse prognostic impact on AML patients in the entire population, and this conclusion same applies to some subgroups like AML patients with ICR, NC, and young AML patients.