Genetic ancestry, differential gene expression, and survival in pediatric B‐cell acute lymphoblastic leukemia

Background Black children have lower incidence yet worse survival than White and Latinx children with B‐cell acute lymphoblastic leukemia (B‐ALL). It is unclear how reported race/ethnicity (RRE) is associated with death in B‐ALL after accounting for differentially expressed genes associated with genetic ancestry. Methods Using Phase 1 and 2 NCI TARGET B‐ALL cases (N = 273; RRE‐Black = 21, RRE‐White = 162, RRE‐Latinx = 69, RRE‐Other = 9, RRE‐Unknown = 12), we estimated proportions of African (AFR), European (EUR), and Amerindian (AMR) genetic ancestry. We estimated hazard ratios (HR) and 95% confidence intervals (95% CI) between ancestry and death while adjusting for RRE and clinical measures. We identified genes associated with genetic ancestry and adjusted for them in RRE and death associations. Results Genetic ancestry varied within RRE (RRE‐Black, AFR proportion: Mean: 78.5%, Range: 38.2%–93.6%; RRE‐White, EUR proportion: Mean: 94%, Range: 1.6%–99.9%; RRE‐Latinx, AMR proportion: Mean: 52.0%, Range: 1.2%–98.7%). We identified 10, 1, and 6 differentially expressed genes (padjusted