Correlation of Cytogenetic Markers with Early Treatment Response Markers in Pediatric ALL: A Single-Center Experience from South India

Acute lymphoblastic leukemia (ALL) accounts for 30% of all pediatric cancers. ALL is biologically a heterogeneous disease with a varied prognosis. Cytogenetic abnormalities and marrow measurable residual disease (MRD) are important independent predictors of survival in ALL. The present study correlated the cytogenetics with early treatment response in pediatric ALL using the Indian Collaborative Childhood Leukemia (ICiCLe)-14 protocol. This article studies the correlation of cytogenetic markers with early treatment response markers in pediatric ALL in pediatric B-cell precursor ALL. This retrospective observational study was conducted at a tertiary care pediatric center in South India from March 2025 to November 2025. A total of 96 children under 12 years were enrolled. Cytogenetic and molecular analyses were performed using G-banded karyotyping and multiplex polymerase chain reaction to detect recurrent abnormalities, including ETV6-RUNX1, BCR-ABL1, TCF3-PBX1, and KMT2A rearrangements. Treatment response was evaluated by assessing steroid response on day 8 and end-of-induction bone marrow MRD using 10-color flow cytometry with a cutoff of 10−4. Of enrolled patients, hyperdiploidy, ETV6-RUNX1, TCF3-PBX1, BCR-ABL1, and MLL rearrangement accounted for 20, 9, 8, 4, and 3%, respectively. Good steroid response was observed in 94% of patients. Overall, 77% achieved MRD negativity postinduction. A statistically significant association was observed between steroid response and MRD in our cohort (p: 0.002). MRD negativity rates were high among patients with ETV6-RUNX1 (78%), hyperdiploidy (74%), normal karyotype (80%), and BCR-ABL1 (75%), with no statistically significant differences between cytogenetic subgroups. Favorable early treatment response and high end-of-induction MRD negativity were observed across cytogenetic subgroups treated with the ICiCLe protocol. Early steroid response correlated significantly with MRD outcomes, underscoring the importance of integrated cytogenetic- and MRD-based risk stratification in pediatric B-ALL.