Prognostic Value of EVI1 Expression in Pediatric Acute Myeloid Leukemia: A Systematic Review

Acute myeloid leukemia (AML) as a distortion of blood cells involves the differentiation of hematopoietic stem cells. Several studies established the irregular overexpression of specific genes is a common finding in patients with AML. The ectopic viral integration site-1 (EVI1) gene is a proto-oncogene subject to alternative splicing, and encodes a zinc-finger protein that acts as a transcriptional regulator in early development. Forced overexpression of EVI1 in hematopoietic progenitors later induced a myeloid differentiation block. The current review aimed at determining the prognostic value of EVI1 expression in patients with AML in the age range of one month to fifteen years. The scientific databases including PubMed, Google Scholar, EMBASE, Scopus, and ISI published up to January 2016 were searched using the conformity keywords and a total of four articles were studied. Three articles declared higher overexpression of EVI1 in patients with mixed-lineage leukemia (MLL) rearrangements. The percentage of overall survival (OS), reported in two articles, decreased in AML patients with high EVI1 expression. A study reported that the relationship between EVI1 expression and OS was negligible in cases with and without EVI1 expression. Another study showed significant differences in event free survival (EFS) and OS in the group of patients with positive MLL-AF9 between EVI1+ and EVI1- patients. The current study revealed that high EVI1 expression was not a poor prognostic factor in pediatric patients with AML. And this gene expression was mainly prognostic concomitantly by other factors such as MLL rearrangement, MEL1 expression, and white blood cell (WBC) count.