Cytogenetics of pre-B-cell acute lymphoblastic leukemia with emphasis on prognostic implications of the t(1;19).
In earlier studies of the cytogenetic characteristics of leukemic lymphoblasts from children with pre-B-cell acute lymphoblastic leukemia (ALL), we concluded that certain chromosomal abnormalities explain, in part, the increased presence of high-risk features at diagnosis and the less favorable response to therapy among patients with this immunologic subclass of ALL. With extended follow-up and a larger patient population, we have further evaluated the biologic and clinical aspects of pre-B leukemia. Of 686 cases of ALL with adequate immunophenotyping, 150 were classified as pre-B cell. Seventy-seven (69%) of the 112 pre-B cases with fully banded karyotypes had a translocation. The t(1;19) accounted for 28 (25%) of these pre-B cases and 31 (6.5%) of all 480 consecutively banded ALL cases. Three (2.6%) of the pre-B cases had a novel dicentric (7;9)(p1?3;p11) translocation. A t(9;22)(q34;q11) and a t(4;11)(q21;q23) were observed in seven (6%) and three (2.6%) of the cases, respectively. Within the pre-B subgroup, comparison of t(1;19) cases (n = 28) with those having other translocations (n = 49) or no identifiable translocations (n = 35) indicated that higher leukocyte counts (P = .002), absence of DNA indexes greater than 1.16 (P = .02), higher serum lactate dehydrogenase levels (P less than .0001), and a higher frequency of nonwhite race (P = .006) were significantly related to the t(1;19). Both the t(1;19) and other chromosomal translocations were associated with an adverse prognosis in the subset of patients treated from 1979 to 1984 (Total Therapy study X). In a more recent and more intensive chemotherapy program (Total Therapy study XI), neither the t(1;19) nor other chromosomal translocations has conferred an inferior outcome, suggesting that effective treatment can offset the negative impact of chromosomal rearrangements in cases of childhood pre-B ALL.
Raimondi
S C
SC
Department of Pathology, St Jude Children's Research Hospital, Memphis, TN 38105.
Behm
F G
FG
Roberson
P K
PK
Williams
D L
DL
Pui
C H
CH
Crist
W M
WM
Look
A T
AT
Rivera
G K
GK
D002648:Child; D002675:Child, Preschool; D002878:Chromosomes, Human, Pair 1; D002888:Chromosomes, Human, Pair 19; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007621:Karyotyping; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000401:mortality; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000401:mortality; D011379:Prognosis; D015996:Survival Rate; D014178:Translocation, Genetic