Pathologic, cytogenetic, and molecular features of acute myeloid leukemia with megakaryocytic differentiation: A report from the Children's Oncology Group

Pediatr Blood Cancer. 2023 May;70(5):e30251. doi: 10.1002/pbc.30251. Epub 2023 Feb 15.

Abstract

Background: Acute myeloid leukemia (AML) with megakaryocytic differentiation (AMkL) is a rare subtype of AML more common in children. Recent literature has identified multiple fusions associated with this type of leukemia.

Methods: Morphology, cytogenetics, and genomic sequencing were assessed in patients from Children's Oncology Group trials AAML0531 and AAML1031 with central-pathology review confirmed non-Down syndrome AMkL. The 5-year event-free survival (EFS), overall survival (OS), and RR were evaluated in these AMkL subcategories.

Results: A total of 107 cases of AMkL (5.5%) were included. Distinct fusions were identified in the majority: RBM15::MRTFA (20%), CBFA2T3::GLIS2 (16%), NUP98 (10%), KMT2A (7%), TEC::MLLT10 (2%), MECOM (1%), and FUS::ERG (1%); many of the remaining cases were classified as AMkL with (other) myelodysplasia-related changes (MRC). Very few cases had AML-associated somatic mutations. Cases with CBFA2T3::GLIS2 were enriched in trisomy 3 (p = .015) and the RAM phenotype, with associated high CD56 expression (p < .001). Cases with NUP98 fusions were enriched in trisomy 6 (p < .001), monosomy 13/del(13q) (p < .001), trisomy 21 (p = .026), and/or complex karyotypes (p = .026). While different 5-year EFS and OS were observed in AMkL in each trial, in general, those with CBFA2T3::GLIS2 or KMT2A rearrangements had worse outcomes compared to other AMkL, while those with RBM15::MRTFA or classified as AMkl-MRC fared better. AMkL with NUP98 fusions also had poor outcomes in the AAML1031 trial.

Conclusion: Given the differences in outcomes, AMkL classification by fusions, cytogenetics, and morphology may be warranted to help in risk stratification and therapeutic options.

Keywords: CBFA2T3::GLIS2; NUP98 fusions; acute megakaryoblastic leukemia; acute myeloid leukemia; pediatric acute myeloid leukemia.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Child
  • Child, Preschool
  • Cytogenetic Analysis
  • Disease-Free Survival
  • Down Syndrome / genetics
  • Female
  • Gene Fusion
  • Humans
  • Infant
  • Leukemia, Myeloid, Acute* / genetics
  • Leukemia, Myeloid, Acute* / mortality
  • Leukemia, Myeloid, Acute* / pathology
  • Male
  • Mutation Rate
  • Young Adult