title: Improved clinical outcome for children with T-lineage acute lymphoblastic leukemia after contemporary chemotherapy: a Children's Cancer Group Study.
abstract: The prognostic importance of T-lineage acute lymphoblastic leukemia (ALL) in contemporary programs of intensive chemotherapy has been controversial. We therefore assessed the impact of this biological feature in risk-adjusted frontline chemotherapy studies of the Children's Cancer Group (CCG), conducted from 1983 to 1994. A substantially greater proportion of T-lineage patients (N = 730) presented with poor-risk features as compared to B-lineage patients (N = 3668) treated in the same studies (71.1% vs. 39.7%, P < 0.0001). Consequently, in the CCG-100 series of clinical trials (1983-1989), which tested regimens that were largely of moderate intensity, T-lineage ALL patients had an excess of adverse early events compared to patients in the B-lineage group: 3-year event-free survival (EFS) estimate, 65.8% vs 78.2% (P < 0.0001). With the introduction of more intensive chemotherapy in studies from 1989 to 1994 (CCG-1800 series). We observed a progressive and significant improvement in the clinical outcome of patients with T-lineage immunophenotype. Three- and 5-year EFS probabilities increased from 65.8% to 78.1% and from 61.0% to 75.2%, respectively, becoming comparable to or slightly better than results for B-lineage ALL patients. When adjusted for the competing effects of leukocyte count, age, organomegaly and other poor-risk features, T-lineage immunophenotype showed no important impact on the overall EFS pattern. These findings demonstrate the loss of adverse prognostic by T-lineage ALL in a large program of intensive chemotherapy developed over the past decade.
authors.affiliation: Children's Cancer Group ALL Biology Reference Laboratory, University of Minnesota, Minneapolis, USA.
authors.forename: F M
authors.initials: FM
authors.lastname: Uckun
authors.forename: G
authors.initials: G
authors.lastname: Reaman
authors.forename: P G
authors.initials: PG
authors.lastname: Steinherez
authors.forename: D C
authors.initials: DC
authors.lastname: Arthur
authors.forename: H
authors.initials: H
authors.lastname: Sather
authors.forename: M
authors.initials: M
authors.lastname: Trigg
authors.forename: D
authors.initials: D
authors.lastname: Tubergen
authors.forename: P
authors.initials: P
authors.lastname: Gaynon
mesh_terms: D000293:Adolescent; D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D007223:Infant; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000188:drug therapy* / Q000401:mortality; D008297:Male; D011379:Prognosis; D016896:Treatment Outcome