title: Clinical significance of deletions of chromosome arm 6q in childhood acute lymphoblastic leukemia: a report from the Children's Cancer Group.
abstract: 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.
authors.affiliation: Department of Genetics, Hughes Institute, St. Paul, MN, USA.
authors.forename: N A
authors.initials: NA
authors.lastname: Heerema
authors.forename: H N
authors.initials: HN
authors.lastname: Sather
authors.forename: M G
authors.initials: MG
authors.lastname: Sensel
authors.forename: M K
authors.initials: MK
authors.lastname: Lee
authors.forename: R
authors.initials: R
authors.lastname: Hutchinson
authors.forename: B J
authors.initials: BJ
authors.lastname: Lange
authors.forename: B C
authors.initials: BC
authors.lastname: Bostrom
authors.forename: J B
authors.initials: JB
authors.lastname: Nachman
authors.forename: P G
authors.initials: PG
authors.lastname: Steinherz
authors.forename: P S
authors.initials: PS
authors.lastname: Gaynon
authors.forename: F M
authors.initials: FM
authors.lastname: Uckun
mesh_terms: 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
chemical_list: D000970:Antineoplastic Agents