Deletion of 7p or monosomy 7 in pediatric acute lymphoblastic leukemia is an adverse prognostic factor: a report from the Children's Cancer Group.
Monosomy 7 or deletions of 7q are associated with many myeloid disorders; however, the significance of such abnormalities in childhood acute lymphoblastic leukemia (ALL) is unknown. Among 1880 children with ALL, 75 (4%) had losses involving chromosome 7, 16 (21%) with monosomy 7, 41 (55%) with losses of 7p (del(7p)), 16 (21%) with losses of 7q (del(7q)), and two (3%) with losses involving both arms. Patients with losses involving chromosome 7 were more likely to be > or =10 years old, National Cancer Institute (NCI) poor risk, and hypodiploid than patients lacking this abnormality. Patients with or without these abnormalities had similar early response to induction therapy. Event-free survival (EFS) and survival for patients with monosomy 7 (P<0.0001 and P=0.0007, respectively) or del(7p) (P<0.0001 and P=0.0001, respectively), but not of patients with del(7q), were significantly worse than those of patients lacking these abnormalities. The poorer EFS was maintained after adjustment for a Philadelphia (Ph) chromosome, NCI risk status, ploidy, or an abnormal 9p. However, the impact on survival was not maintained for monosomy 7 after adjustment for a Ph. These results indicate that the critical region of loss of chromosome 7 in pediatric ALL may be on the p-arm.
Heerema
N A
NA
The Ohio State University, Columbus, OH, USA. heerema-1@medctr.osu.edu
Nachman
J B
JB
Sather
H N
HN
La
M K
MK
Hutchinson
R
R
Lange
B J
BJ
Bostrom
B
B
Steinherz
P G
PG
Gaynon
P S
PS
Uckun
F M
FM
D002648:Child; D002675:Child, Preschool; D002872:Chromosome Deletion; D002897:Chromosomes, Human, Pair 7; D006801:Humans; D009006:Monosomy; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000401:mortality; D011379:Prognosis