Clinical features and treatment outcome of children with biphenotypic CD2+ CD19+ acute lymphoblastic leukemia: a Children's Cancer Group study.
Leukemic cells from a subset of children with acute lymphoblastic leukemia (ALL) express lymphoid antigens of both T lineage and B lineage, but the clinical significance of this immunophenotype is unknown. We now report the first comprehensive comparison of treatment outcomes among a large cohort of children with CD2+ CD19+ biphenotypic ALL (N = 77), B-lineage ALL (BL) (N = 1,631), or T-lineage ALL (TL) (N = 347) ALL who were treated on risk-adjusted Children's Cancer Group (CCG) protocols. CD2+ CD19+ patients were more similar to BL than TL patients with respect to presenting features and antigen expression. The percentages of patients achieving successful induction therapy outcome were 98.7%, 97.8%, and 97.3% for CD2+ CD19+, BL, and TL patients, respectively. Univariate comparisons of 4-year event-free survival (83.7%, 72.8%, 75.2% for CD2+ CD19+, BL, and TL patients, respectively) achieved borderline significance (CD2+ CD19+ B, P = .08; CD2+ CD19+ v T, P = .07). Relative hazard rate (RHR) estimates for BL and TL compared with CD2+ CD19+ were 1.79 and 1.90, respectively, implying a better outcome for biphenotypic patients. However, multivariate adjusted RHRs for BL and TL compared with CD2+ CD19+ were 1.43 (P = .29) and 1.16 (P = .76), respectively, suggesting a significant reduction in risk for BL or TL patients once adjustment was made for the more favorable characteristics of the CD2+ CD19+ group. Thus, pediatric ALL patients treated on contemporary CCG protocols who present with CD2+ CD19+ biphenotypic leukemia generally have good treatment outcomes, due in part to their favorable presenting features.
Uckun
F M
FM
Biotherapy Institute, University of Minnesota, Roseville 55113, USA.
Gaynon
P
P
Sather
H
H
Arthur
D
D
Trigg
M
M
Tubergen
D
D
Nachman
J
J
Steinherz
P
P
Sensel
M G
MG
Reaman
G R
GR
D000293:Adolescent; D018941:Antigens, CD19 / Q000032:analysis*; D000943:Antigens, Differentiation / Q000032:analysis*; D000951:Antigens, Neoplasm / Q000032:analysis*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D018801:CD2 Antigens / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007223:Infant; D015448:Leukemia, B-Cell / Q000188:drug therapy / Q000401:mortality / Q000473:pathology; D015458:Leukemia, T-Cell / Q000188:drug therapy / Q000401:mortality / Q000473:pathology; D015993:Life Tables; D008297:Male; D014411:Neoplastic Stem Cells / Q000276:immunology*; D010641:Phenotype; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy / Q000401:mortality / Q000473:pathology*; D012074:Remission Induction; D016896:Treatment Outcome
D018941:Antigens, CD19; D000943:Antigens, Differentiation; D000951:Antigens, Neoplasm; D018801:CD2 Antigens