title: Prognosis of children with acute lymphoblastic leukemia (ALL) and intrachromosomal amplification of chromosome 21 (iAMP21).
abstract: Patients with acute lymphoblastic leukemia (ALL) and an intrachromosomal amplification of chromosome 21 (iAMP21) comprise a novel and distinct biological subgroup. We prospectively screened 1630 (84%) patients treated on the UK MRC ALL97 protocol for iAMP21 and herein present demographic, clinical, and survival data on the 28 (2%) children found to harbor this abnormality. They had a common or pre-B ALL immunophenotype, were significantly older (median 9 years vs 5 years), and had a lower white cell count (median 3.9 vs 12.4) compared with children without this abnormality. Notably, patients with iAMP21 had a significantly inferior event-free and overall survival at 5 years compared with other patients: 29% (95% confidence interval [CI], 13%-48%) versus 78% (95% CI, 76%-80%) and 71% (95% CI, 51%-84%) versus 87% (95% CI, 85%-88%), respectively. As a result of this 3-fold increase in relapse risk, newly diagnosed patients with iAMP21 recruited to the current UK MRC ALL2003 trial are being treated on the high-risk arm and are considered for bone marrow transplantation in first remission.
authors.affiliation: Leukaemia Research Cytogenetics Group, Cancer Sciences Division, University of Southampton, United Kingdom. avm@soton.ac.uk
authors.forename: Anthony V
authors.initials: AV
authors.lastname: Moorman
authors.forename: Susan M
authors.initials: SM
authors.lastname: Richards
authors.forename: Hazel M
authors.initials: HM
authors.lastname: Robinson
authors.forename: Jon C
authors.initials: JC
authors.lastname: Strefford
authors.forename: Brenda E S
authors.initials: BE
authors.lastname: Gibson
authors.forename: Sally E
authors.initials: SE
authors.lastname: Kinsey
authors.forename: Tim O B
authors.initials: TO
authors.lastname: Eden
authors.forename: Ajay J
authors.initials: AJ
authors.lastname: Vora
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Mitchell
authors.forename: Christine J
authors.initials: CJ
authors.lastname: Harrison
mesh_terms: D002648:Child; D002675:Child, Preschool; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics*; D003582:Cytogenetics; D005260:Female; D005784:Gene Amplification / Q000235:genetics*; D006801:Humans; D007223:Infant; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000473:pathology*; D011379:Prognosis; D015996:Survival Rate