Non-classical karyotypic features in relapsed childhood B-cell precursor acute lymphoblastic leukemia.
Karyotype analysis of acute lymphoblastic leukemia (ALL) at diagnosis has provided valuable prognostic markers for treatment stratification. However, reports of cytogenetic studies of relapsed ALL samples are limited. We compared the karyotypes from 436 nonselected B-cell precursor ALL patients at initial diagnosis and of 76 patients at first relapse. We noticed a relative increase of karyotypes that did not fall into the classic ALL cytogenetic subgroups (high hyperdiploidy, t(12;21), t(9;22), 11q23, t(1;19), <45 chromosomes) in a group of 29 patients at relapse (38%) compared to 130 patients at presentation (30%). Non-classical cytogenetic aberrations in these 29 patients were mostly found on chromosomes 1, 2, 7, 9, 13, 14, and 17. We also describe six rare reciprocal translocations, three of which involved 14q32. The most frequent abnormalities were found in 9p (12/29 cases) and were associated with a marked decrease in the duration of the second remission, but not of the probability of 10-year event-free survival after relapse treatment. From 29 patients with non-classical cytogenetic aberrations, only 8 (28%) had been stratified to a high risk-arm on the first treatment protocol, suggesting that this subgroup might benefit from the identification of new prognostic markers in future studies.
Wehrli
Lea A
LA
Division of Oncology, University Children's Hospital, Steinwiesstrasse 75, CH-8032 Zurich, Switzerland.
Braun
Julia
J
Buetti
Luisa Nobile
LN
Hagleitner
Nicole
N
Hengartner
Heinz
H
Kühne
Thomas
T
Lüer
Sonja
S
Ozsahin
Hulya
H
Popovic
Maja Beck
MB
Niggli
Felix K
FK
Betts
David R
DR
Bourquin
Jean-Pierre
JP
D000208:Acute Disease; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations; D005260:Female; D006801:Humans; D007223:Infant; D007621:Karyotyping; D008297:Male; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000517:prevention & control; D012008:Recurrence; D014178:Translocation, Genetic; D016896:Treatment Outcome