Abnormalities of chromosome bands 13q12 to 13q14 in childhood acute lymphoblastic leukemia.
OBJECTIVE
Little is known about nonrandom deletions of chromosome bands 13q12 to 13q14 (13q12-14) in acute lymphoblastic leukemia (ALL). We determined the prognostic significance of cytogenetically identified breakpoints in 13q12-14 in children with newly diagnosed ALL treated on Children's Cancer Group protocols from 1988 to 1995.


METHODS
Breakpoints in 13q12-14 were identified in 36 (2%) of the 1,946 cases with accepted cytogenetic data. Outcome analysis used standard life-table methods.


RESULTS
Seventeen patients (47%) with an abnormal 13q12-14 were classified, according to the National Cancer Institute (NCI), as poor risk, and 15 patients (42%) were standard risk; four (11%) were infants less than 12 months of age. Eight cases had balanced rearrangements of 13q12-14, 27 patients had a partial loss of 13q, and one had both a partial gain and a partial loss. The most frequent additional abnormalities among these patients were an abnormal 12p, a del(6q), a del(9p), a 14q11 breakpoint, and an 11q23 breakpoint. Nineteen patients were pseudodiploid, 10 were hyperdiploid, and seven were hypodiploid. Patients with an abnormal 13q12-14 had significantly worse event-free survival than patients lacking such an abnormality, with estimates at 6 years of 61% (SD = 14%) and 74% (SD = 1%), respectively (P =.04; relative risk = 1.74). Overall survival, however, was similar for the two groups (P =.25). The prognostic effect of an abnormal 13q was attenuated in a multivariate analysis adjusted for NCI risk status and ploidy (P =.72).


CONCLUSIONS
Aberrations of 13q12-14 may contribute to leukemogenesis of childhood ALL and confer increased risk of treatment failure but are associated with other poor-risk features.
Heerema
N A
NA
Department of Genetics, Parker Hughes Institute, St Paul, Minnesota, USA.
Sather
H N
HN
Sensel
M G
MG
Lee
M K
MK
Hutchinson
R J
RJ
Nachman
J B
JB
Reaman
G H
GH
Lange
B J
BJ
Steinherz
P G
PG
Bostrom
B C
BC
Gaynon
P S
PS
Uckun
F M
FM
D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations; D019457:Chromosome Breakage; D002872:Chromosome Deletion; D002882:Chromosomes, Human, Pair 13; D002986:Clinical Trials as Topic; D015331:Cohort Studies; D018572:Disease-Free Survival; D006801:Humans; D007223:Infant; D007621:Karyotyping; D011003:Ploidies; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000628:therapy; D016896:Treatment Outcome