The Impact of IKZF1 Deletion on the Prognosis of Acute Lymphoblastic Leukemia: an Updated Meta-analysis

Background: Various studies have reported that IKZF1 deletion (IKZF1-d) is a poor prognostic factor for acute lymphoblastic leukemia (ALL) patients, however they do not agree on the level of significance for this deletion.

Objective: To provide a quantitative assessment of this correlation, an updated meta-analysis of cohort studies was performed to derive a more precise estimation of the prognostic significance of IKZF1-d.

Methods: Relevant studies were identified in PubMed, Embase, Cochrane, Web of Science, China National Knowledge Infrastructure (CNKI) and Wanfang databases until January 31, 2014. A total of 15 published studies including 5021 patients were eligible for this meta-analysis. Combined hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated with random-effects model.

Results: Combined hazard ratios suggested that IKZF1 deletion (IKZF1-d) had an unfavorable impact on event-free survival (EFS) (HR=2.32, 95%CI: 1.97-2.74) and overall survival (OS) (HR=2.56, 95%CI: 1.75-3.74) in patients with ALL. The significant role of IKZF1-d in the prognosis of ALL was also observed among different subgroups stratified by statistical methodology, ethnicity, age, detection method, risk group and duration of follow up.

Conclusions: The findings from this meta-analysis suggest that IKZF1 deletion can be used to serve as an independent predictive factor in patients with ALL.