Prognosis of children with acute lymphoblastic leukemia (ALL) and intrachromosomal amplification of chromosome 21 (iAMP21).
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.
Moorman
Anthony V
AV
Leukaemia Research Cytogenetics Group, Cancer Sciences Division, University of Southampton, United Kingdom. avm@soton.ac.uk
Richards
Susan M
SM
Robinson
Hazel M
HM
Strefford
Jon C
JC
Gibson
Brenda E S
BE
Kinsey
Sally E
SE
Eden
Tim O B
TO
Vora
Ajay J
AJ
Mitchell
Christopher D
CD
Harrison
Christine J
CJ
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