Prognosis of pediatric BCP‐ALL with IKZF1 deletions and impact of intensive chemotherapy: Results of SCCLG‐2016 study

Abstract

AbstractBackgroundIKZF1 deletion (IKZF1del) is associated with poor prognosis in B‐cell precursor acute lymphoblastic leukemia (BCP‐ALL). But the prognosis of IKZF1del combined with other prognostic stratification factors remains unclear. Whether intensified treatment improves BCP‐ALL prognosis has not been determined.MethodsA retrospective analysis was performed on 1291 pediatric patients diagnosed with BCP‐ALL and treated with the South China Children's Leukemia 2016 protocol. Patients were stratified based on IKZF1 status for comparison of characteristics and outcome. Additionally, IKZF1del patients were further divided based on chemotherapy intensity for outcome assessments.ResultsThe BCP‐ALL pediatric patients with IKZF1del in south China showed poorer early response. Notably, the DFS and OS for IKZF1del patients were markedly lower than IKZF1wt group (3‐year DFS: 88.7% [95% CI: 83.4%–94.0%] vs. 93.5% [95% CI: 92.0%–94.9%], P = .021; 3‐year OS: 90.7% [95% CI: 85.8% to 95.6%] vs. 96.1% [95% CI: 95% to 97.2%, P = .003]), with a concurrent increase in 3‐year TRM (6.4% [95% CI: 2.3%–10.5%] vs. 2.9% [95% CI: 1.9%–3.8%], P = .025). However, the 3‐year CIR was comparable between the two groups (5.7% [95% CI: 1.8%–9.5%] vs. 3.7% [95% CI: 2.6%–4.7%], P = .138). Subgroup analyses reveal no factor significantly influenced the prognosis of the IKZF1del cohort. Noteworthy, intensive chemotherapy improved DFS from 85.7% ± 4.1% to 94.1% ± 0.7% in IKZF1del group (P = .084). Particularly in BCR::ABL positive subgroup, the 3‐year DFS was remarkably improved from 53.6% ± 20.1% with non‐intensive chemotherapy to 100% with intensive chemotherapy (P = .026).ConclusionsPediatric BCP‐ALL patients with IKZF1del in South China manifest poor outcomes without independent prognostic significance. While no factor substantially alters the prognosis in the IKZF1del group. Intensified chemotherapy may reduce relapse rates and improve DFS in patients with IKZF1del subset, particularly in IKZFdel patients with BCR::ABL positive.