Clinical significance of deletions of chromosome arm 6q in childhood acute lymphoblastic leukemia: a report from the Children's Cancer Group.
We have compared outcome for 167 (9.0%) children with a del(6q) and 1713 (91%) children without a del(6q) treated on Children's Cancer Group (CCG) risk-adjusted treatment protocols for acute lymphoblastic leukemia (ALL). Thirty-three patients had a del(6q) as the sole aberration; 22 patients had a del(6q) only as a secondary abnormality. Thirty-six cases had a del(6q) and high hyperdiploidy (>50 chromosomes). Six patients with a del(6q) also had +16 and 8 patients had loss of a sex chromosome. Frequent recurring breakpoints were q13, q15, q21, q23, and q25. Patients with a del(6q) were more likely to have T-lineage ALL (p < 0.001), a mediastinal mass (p = 0.01), and higher WBC counts (p = 0.04), although only half of these patients were classified as poor risk. Event-free survival at 6 years was similar for patients with or without a del(6q), with estimates of 77% (SD = 5%) and 74% (SD = 2%), respectively (p = 0.44). This finding was also observed within NCI poor and standard risk groups. Thus, cytogenetically detectable del(6q) is not associated with adverse risk in pediatric ALL.
Heerema
N A
NA
Department of Genetics, Hughes Institute, St. Paul, MN, USA.
Sather
H N
HN
Sensel
M G
MG
Lee
M K
MK
Hutchinson
R
R
Lange
B J
BJ
Bostrom
B C
BC
Nachman
J B
JB
Steinherz
P G
PG
Gaynon
P S
PS
Uckun
F M
FM
D000970:Antineoplastic Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D002872:Chromosome Deletion; D002896:Chromosomes, Human, Pair 6; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D011379:Prognosis
D000970:Antineoplastic Agents