title: Prognostic factors in the acute lymphoid and myeloid leukemias of infants.
abstract: The age boundaries and prognostic factors that define the infant leukemias are still controversial. We therefore analyzed event-free survival according to age group in 96 children treated for acute lymphoblastic leukemia (ALL) and 51 treated for acute myeloid leukemia (AML) before the age of 2 years. The study population was registered in consecutive institutional trials of multiagent chemotherapy conducted between 1980 and 1994. Among infants with ALL, event-free survival was significantly poorer in the 0- to 6-month-old group than in patients treated between 6 and 12 months of age (P = 0.03), whose outcome was in turn inferior to that in the 12- to 18-month and 18- to 24-month age groups (P = 0.013). Leukemic cells from ALL patients younger than 12 months had a significantly higher frequency of 11q23/MLL abnormalities, as well as better growth in stromal cell culture, compared to lymphoblasts from the older groups (P < 0.01). The only independent predictor of adverse prognosis among infants diagnosed with ALL before age 12 months was the presence of an 11q23/MLL rearrangement (P = 0.03). These findings contrast sharply with results for the AML cohort, whose event-free survival did not vary significantly by age group (P = 0.58). Male sex (P = 0.01) and leukocyte count > or = 50 x 10(9/l) (P = 0.04), but not 11q23 abnormalities, were independently associated with a poorer outcome for children with AML younger than 12 months at diagnosis. Thus, in very young children with ALL (but not AML), the rearrangement status of the 11q23/MLL region supersedes age group as a determinant of treatment outcome.
authors.affiliation: Department of Hematology-Oncology, St Jude Children's Research Hospital, Memphis, TN 38101-0318, USA.
authors.forename: C H
authors.initials: CH
authors.lastname: Pui
authors.forename: R C
authors.initials: RC
authors.lastname: Ribeiro
authors.forename: D
authors.initials: D
authors.lastname: Campana
authors.forename: S C
authors.initials: SC
authors.lastname: Raimondi
authors.forename: M L
authors.initials: ML
authors.lastname: Hancock
authors.forename: F G
authors.initials: FG
authors.lastname: Behm
authors.forename: J T
authors.initials: JT
authors.lastname: Sandlund
authors.forename: G K
authors.initials: GK
authors.lastname: Rivera
authors.forename: W E
authors.initials: WE
authors.lastname: Evans
authors.forename: W M
authors.initials: WM
authors.lastname: Crist
authors.forename: R
authors.initials: R
authors.lastname: Krance
mesh_terms: D000367:Age Factors; D002869:Chromosome Aberrations; D002880:Chromosomes, Human, Pair 11; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007223:Infant; D015470:Leukemia, Myeloid, Acute / Q000097:blood / Q000235:genetics / Q000401:mortality*; D007958:Leukocyte Count; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000097:blood / Q000235:genetics / Q000401:mortality*; D011379:Prognosis; D012737:Sex Factors