Ploidy and clinical characteristics of childhood acute myeloid leukemia: A NOPHO-AML study
Menée sur 596 patients pédiatriques atteints d'une leucémie myéloïde aiguë, cette étude analyse les anomalies du caryotype en association avec les caractéristiques cliniques des patients
We report the first large series (n = 596) of pediatric acute myeloid leukemia (AML) focusing on modal numbers (MN) from the population-based NOPHO-AML trials. Abnormal karyotypes were present in 452 cases (76%) and numerical aberrations were present in 40% (n = 237) of all pediatric AML. Among patients with an abnormal karyotype, the MN 46 was most common (n = 251; 56%) of which 36 (8%) were pseudodiploid with numerical aberrations, followed by MN 47 (n = 80; 18%) and MN 43–45 (n = 48; 8%). No cases had MN less than 43. Hyperdiploid AML with MN 48–65 comprised 11% of all cases and was associated with early onset (median age 2 years), female sex (57%), and a dominance of acute megakaryoblastic leukemia (AMKL) (29%). Hypodiploidy constituted 8% of all AML and was associated with older age (median age 9 years), male predominance (60%), FAB M2 (56%), and t(8;21)(q22;q22) (56%) with loss of sex chromosomes. Inferior outcome was observed for hypodiploid cases (5-year event-free survival 40% and 5-year overall survival 40%) but did not reach statistical significance. Chromosomes were gained in a nonrandom pattern, where chromosomes 8, 21, 19, and 6 were the most commonly gained. In conclusion, based on MNs, two cytogenetic subgroups with characteristic clinical features are described; hypodiploidy found in 8% and associated with high median age, male sex, t(8;21)(q22;q22), and FAB M2 and possibly associated with inferior outcome (P = 0.13), and hyperdiploidy with MN 48–65 in 11% associated with early onset, female sex, and AMKL. © 2014 Wiley Periodicals, Inc.