Ch. Pui et al., IMMUNOLOGICAL, CYTOGENETIC, AND CLINICAL CHARACTERIZATION OF CHILDHOOD ACUTE LYMPHOBLASTIC-LEUKEMIA WITH THE T(1-19)(Q23-P13) OR ITS DERIVATIVE, Journal of clinical oncology, 12(12), 1994, pp. 2601-2606
Purpose: To evaluate the immunophenotypes, karyotypes, and clinical fe
atures, including treatment responses, of patients with childhood acut
e lymphoblastic leukemia (ALL) and either a t(1;19)(q23;p13) or a der(
l9)t(1;19)(q23;p13) translocation. Patients and Methods: The lymphobla
sts of 45 patients with a balanced translocation, t(1;19) or its deriv
ative form, der (19)t(1;19), were analyzed by cytogenetic and immunolo
gic methods for differences that might suggest distinct subtypes of AL
L. This cohort was treated in four consecutive clinical trials with a
median overall follow-up duration of 7 years. Results: A pre-B immunop
henotype was found in 10 cases with the balanced t(1;19) and 31 with t
he unbalanced der(19)t(1;19). The four remaining cases, each with a de
rivative t(1;19), were classified as early pre-B ALL. The characterist
ic surface antigen profile of the 41 pre-B cases was CD19(+)/CD10(+)/C
D22(+)/CD34(-)/CD20(+/-), whether the translocation was balanced or de
rivative. In contrast to the four early pre-B cases, which held hyperd
iploid karyotypes (> 50 chromosomes), the pre-B cases were primarily p
seudodiploid, Comparison of presenting clinical and laboratory feature
s, as well as event-free survival, failed to disclose any differences
that would warrant separation of pre-B cases with a balanced or deriva
tive translocation. However, neither subgroup responded to therapy as
well as patients with early pre-B ALL, each of whom remains in complet
e remission for greater than or equal to 3 years. Conclusion: 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 i
ntensive chemotherapy. The exceptional cases have an early pre-B pheno
type with hyperdiploid karyotypes and appear to have favorable prognos
is. (C) 1994 by American Society of Clinical Oncology.