Immunologic, cytogenetic, and clinical characterization of childhood acute lymphoblastic leukemia with the t(1;19) (q23; p13) or its derivative.
OBJECTIVE
To evaluate the immunophenotypes, karyotypes, and clinical features, including treatment responses, of patients with childhood acute lymphoblastic leukemia (ALL) and either a t(1;19)(q23;p13) or a der(19)t(1;19)(q23;p13) translocation.


METHODS
The lymphoblasts of 45 patients with a balanced translocation, t(1;19) or its derivative form, der(19)t(1;19), were analyzed by cytogenetic and immunologic methods for differences that might suggest distinct subtypes of ALL. This cohort was treated in four consecutive clinical trials with a median overall follow-up duration of 7 years.


RESULTS
A pre-B immunophenotype was found in 10 cases with the balanced t(1;19) and 31 with the unbalanced der(19)t(1;19). The four remaining cases, each with a derivative t(1;19), were classified as early pre-B ALL. The characteristic surface antigen profile of the 41 pre-B cases was CD19+/CD10+/CD22+/CD34-/CD20+/-, whether the translocation was balanced or derivative. In contrast to the four early pre-B cases, which had hyperdiploid karyotypes (> 50 chromosomes), the pre-B cases were primarily pseudodiploid. Comparison of presenting clinical and laboratory features, as well as event-free survival, failed to disclose any differences that would warrant separation of pre-B cases with a balanced or derivative translocation. However, neither subgroup responded to therapy as well as patients with early pre-B ALL, each of whom remains in complete remission for > or = 3 years.


CONCLUSIONS
The t(1;19) and the der(19)t(1;19) identify a relatively homogeneous group of patients with pre-B ALL, who can be expected to respond similarly to intensive chemotherapy. The exceptional cases have an early pre-B phenotype with hyperdiploid karyotypes and appear to have favorable prognosis.
Pui
C H
CH
Department of Hematology-Oncology, St Jude Children's Research Hospital, Memphis, TN 38101.
Raimondi
S C
SC
Hancock
M L
ML
Rivera
G K
GK
Ribeiro
R C
RC
Mahmoud
H H
HH
Sandlund
J T
JT
Crist
W M
WM
Behm
F G
FG
D000293:Adolescent; D015703:Antigens, CD / Q000032:analysis; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D004273:DNA, Neoplasm / Q000032:analysis; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D007223:Infant; D007621:Karyotyping; D007958:Leukocyte Count; D008297:Male; D011003:Ploidies; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000276:immunology / Q000628:therapy; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000276:immunology / Q000628:therapy; D014178:Translocation, Genetic
D015703:Antigens, CD; D004273:DNA, Neoplasm