Intrachromosomal amplification of chromosome 21 in Egyptian pediatric B-lineage acute lymphoblastic leukemia: a hospital-based observational study

Abstract

Abstract Objective This study was conducted to evaluate the clinicopathologic features as well as the association between the intrachromosomal amplification of chromosome 21 (iAMP21) and the clinical outcome in Egyptian patients with B-cell acute lymphoblastic leukemia (B-ALL) attending/admitted in the Department of Pediatric Oncology of our university hospital. Patients and methods This was a prospective study conducted on 25 newly diagnosed and five relapsed pediatric patients with B-ALL (23 males and seven females), with a mean age of 7.76 ± 5.11 years. Bone marrow aspiration was done to diagnose and evaluate remission of participants, and fluorescence in situ hybridization (FISH) analysis using the ETV6-RUNX1 probes was used to detect RUNX1 amplification. Results iAMP21 was identified in 28% of newly diagnosed patients with B-ALL and in 80% of relapsed cases with B-ALL. There was a significant association between positive iAMP21 cases and failure to attain complete remission at day 28 (P=0.004). A significant relationship among the 14 patients monitored for disease outcome was found between the presence of iAMP21 and occurrence of relapse or death in newly diagnosed, or failure to achieve complete remission or death in relapsed cases (P=0.036). Conclusion There was a higher incidence of iAMP21 among our Egyptian pediatric B-ALL cases and unfavorable effect of iAMP21 on patients’ prognosis even with coexistence of ETV6-RUNX1.