Pooled Prevalence, Subtypes, and Determinants of Leukemia among Children with Cancer: A Systematic Review and Meta-Analysis

Abstract

Background
Leukemia is the most common childhood cancer, characterized by abnormal proliferation of immature white blood cells. However, evidence on its global burden, subtype distribution, and determinants remains fragmented and region-specific. This systematic review and meta-analysis (SRMA) aimed to estimate the global pooled prevalence, subtype distribution, and determinants of leukemia among children with cancer.
Methods
Four databases, PubMed, EMBASE, SCOPUS, and Google Scholar, were searched for studies published between 2010 and 2025. Studies reporting the number or prevalence of childhood leukemia and its subtypes, or associated risk factors, were included. The SRMA followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and risk of bias was assessed using NIH quality assessment tool. Forest plots were used to present pooled estimates, and funnel plots to assess publication bias. The SRMA was registered in Prospective Register of Systematic Reviews (PROSPERO) (Reg. No. CRD420251059126).    
Results
Forty-two studies involving 74,485 children with cancer were included. The pooled prevalence of leukemia was 28% (95% CI: 21-36), with acute lymphoblastic leukemia (ALL) accounting for 80% (95% CI: 77-83), acute myeloid leukemia (AML)  17% (95% CI: 14-19), and chronic myeloid leukemia (CML) 4% (95% CI: 3-6) . Maternal and parental pesticide exposure was the most common risk factor associated with childhood leukemia, alongside older age of mothers and fathers, maternal and paternal education, high birth weight of the child, family history of leukemia, parental smoking, living near high-voltage power lines, and benzene exposure. 
Conclusions
Leukemia accounted for nearly one-third of pediatric cancer cases globally, with ALL being the predominant subtype. Consistently reported risk factors included parental pesticide/insecticide exposure, older parental age, maternal education, high birth weight, family history of leukemia, parental smoking, proximity to high-voltage power lines, and benzene exposure. These findings highlight the need for targeted prevention, early detection, and public health interventions to reduce the burden of childhood leukemia.