title: Minimally differentiated acute myeloid leukemia (FAB AML-M0) is associated with an adverse outcome in children: a report from the Children's Oncology Group, studies CCG-2891 and CCG-2961.
abstract: To assess the impact of minimally differentiated acute myeloid leukemia (AML-M0) morphology in children, we analyzed 2 sequential Children's Cancer Group AML clinical trials. We compared presenting characteristics and outcomes of 82 CCG-2891 and CCG-2961 patients with de novo, non-Down syndrome (DS) AML-M0 with those of 1620 patients with non-M0 AML, and of 10 CCG-2891 patients with DS-associated AML-M0 with those of 179 with DS-associated non-M0 AML. Morphology and cytogenetics were centrally reviewed. The non-DS AML-M0 children had a lower white blood cell (WBC) count (P = .001) than their non-M0 counterparts and a higher incidence of chromosome 5 deletions (P = .002), nonconstitutional trisomy 21 (P = .027), and hypodiploidy (P = .002). Outcome analyses considering all children with non-DS AML demonstrated no significant differences between M0 and non-M0 patients. Analyses restricted to intensive-timing CCG-2891 and CCG-2961 demonstrated comparable complete response (CR) rates (79% and 78%) between non-DS M0 and non-M0 patients. Overall survival (OS) from diagnosis (38% +/- 14% versus 51% +/- 3%; P = .160) was not significantly different between the 2 groups. OS from end of induction (45% +/- 17% versus 63% +/- 3%; P = .038), event-free survival (EFS; 23% +/- 11% versus 41% +/- 3%; P = .018), and disease-free survival (DFS; 31% +/- 14% versus 52% +/- 3%; P = .009) were inferior in the M0 group. There was no significant outcome difference between DS-associated AML-M0 and non-M0 children. This study suggests that intensively treated non-DS-associated AML-M0 children have an inferior outcome compared with children with non-M0 AML.
authors.affiliation: Division of Hematology/Oncology/BMT, BC's Children's Hospital, Vancouver, BC, Canada. dragmatt96@optusnet.com.au
authors.forename: Draga
authors.initials: D
authors.lastname: Barbaric
authors.forename: Todd A
authors.initials: TA
authors.lastname: Alonzo
authors.forename: Robert B
authors.initials: RB
authors.lastname: Gerbing
authors.forename: Soheil
authors.initials: S
authors.lastname: Meshinchi
authors.forename: Nyla A
authors.initials: NA
authors.lastname: Heerema
authors.forename: Dorothy R
authors.initials: DR
authors.lastname: Barnard
authors.forename: Beverly J
authors.initials: BJ
authors.lastname: Lange
authors.forename: William G
authors.initials: WG
authors.lastname: Woods
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Arceci
authors.forename: Franklin O
authors.initials: FO
authors.lastname: Smith
mesh_terms: D000293:Adolescent; D000328:Adult; D002454:Cell Differentiation; D002648:Child; D002675:Child, Preschool; D003582:Cytogenetics; D018572:Disease-Free Survival; D004314:Down Syndrome / Q000473:pathology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology*; D008297:Male; D008495:Medical Oncology; D009367:Neoplasm Staging; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome