Intrachromosomal Amplification of Chromosome 21 Is Associated With Inferior Outcomes in Children With Acute Lymphoblastic Leukemia Treated in Contemporary Standard-Risk Children's Oncology Group Studies: A Report From the Children's Oncology Group.

摘要

Five-year overall survival (OS) for children with B-cell precursor acute lymphoblastic leukemia (B-ALL) exceeds 90% with risk-adapted therapy. Age, initial WBC count, genetic aberrations, and minimal residual disease (MRD) are used for risk stratification. Intrachromosomal amplification of a region of chromosome 21 (iAMP21; three or more extra copies of RUNX1 on an abnormal chromosome 21) is a recently identified recurrent genomic lesion associated with inferior outcome in some studies. We investigated the impact of iAMP21 in a large cohort treated in contemporary Children's Oncology Group (COG) ALL trials.Fluorescent in situ hybridization for specific genetic aberrations was required at diagnosis. MRD was measured by flow cytometry at end induction. Outcome was measured as event-free survival (EFS) and OS.iAMP21 was found in 158 (2%) of 7,793 patients with B-ALL age ≥ 1 year; 74 (1.5%) of 5,057 standard-risk (SR) patients, and 84 (3.1%) of 2,736 high-risk (HR) patients.