title: CD2 antigen expression on leukemic cells as a predictor of event-free survival after chemotherapy for T-lineage acute lymphoblastic leukemia: a Children's Cancer Group study.
abstract: We examined the prognostic impact of CD2 antigen expression for 651 patients with T-lineage acute lymphoblastic leukemia (ALL), who were enrolled in front-line Childrens Cancer Group treatment studies between 1983 and 1994. There was a statistically significant correlation between the CD2 antigen positive leukemic cell content of bone marrow and probability of remaining in bone marrow remission, as well as overall event-free survival (EFS) (P = .0003 and P = .002, log-rank tests for linear trend). When compared with patients with the highest CD2 expression level (> 75% positivity), the life table relative event rate (RER) was 1.22 for patients with intermediate range CD2 expression level (30% to 75% positivity) and 1.81 for "CD2-negative" patients (< 30% positivity). At 6 years postdiagnosis, the EFS estimates for the three CD2 expression groups (low positivity to high positivity) were 52.8%, 65.5%, and 71.9%, respectively. CD2 expression remained a significant predictor of EFS after adjustment for the effects of other covariates by multivariate regression, with a RER of 1.47 for CD2-negative patients (P = .04). Analysis of T-lineage ALL patients shows a significant separation in EFS after adjustment for the National Cancer Institute (NCI) age and white blood cell (WBC) criteria for standard and high-risk ALL (P = .002, RER = 1.67). The determination of CD2 expression on leukemic cells helped identify patients with the better and poorer prognoses in both of these risk group subsets. For standard risk T-lineage ALL, CD2-negative patients had a worse outcome (P = .0007, RER = 2.92) with an estimated 5-year EFS of 55.9% as compared with 78.3% for the CD2-positive patients. Thus, CD2 negativity in standard risk T-lineage ALL identified a group of patients who had a worse outcome than high-risk T-lineage ALL patients who were CD2 positive. The percentage of CD2 antigen positive leukemic cells from T-lineage ALL patients is a powerful predictor of EFS after chemotherapy. This prognostic relationship is the first instance in which a biological marker in T-lineage ALL has been unequivocally linked to treatment outcome.
authors.affiliation: Children's Cancer Group ALL Biology Reference Laboratory, University of Minnesota, Minneapolis 55113, USA.
authors.forename: F M
authors.initials: FM
authors.lastname: Uckun
authors.forename: P G
authors.initials: PG
authors.lastname: Steinherz
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: Arthur
authors.forename: D
authors.initials: D
authors.lastname: Tubergen
authors.forename: P
authors.initials: P
authors.lastname: Gaynon
authors.forename: G
authors.initials: G
authors.lastname: Reaman
mesh_terms: D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000032:analysis; D000951:Antigens, Neoplasm / Q000032:analysis*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000032:analysis*; D001853:Bone Marrow / Q000473:pathology; D018801:CD2 Antigens / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D018572:Disease-Free Survival; D005260:Female; D006529:Hepatomegaly / Q000209:etiology / Q000473:pathology; D006801:Humans; D007223:Infant; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000188:drug therapy / Q000276:immunology / Q000401:mortality* / Q000473:pathology; D015993:Life Tables; D008297:Male; D014411:Neoplastic Stem Cells / Q000276:immunology / Q000473:pathology; D011379:Prognosis; D012306:Risk; D013163:Splenomegaly / Q000209:etiology / Q000473:pathology; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D015703:Antigens, CD; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D018801:CD2 Antigens