title: Clinical and cytogenetic features of pediatric dic(9;20)(p13.2;q11.2)-positive B-cell precursor acute lymphoblastic leukemias: a Nordic series of 24 cases and review of the literature.
abstract: Although dic(9;20)(p13.2;q11.2) is a characteristic abnormality in childhood B-cell precursor acute lymphoblastic leukemias (BCP ALL), little is known about its clinical impact or the type and frequency of additional aberrations it may occur together with. We here review the clinical and cytogenetic features of a Nordic pediatric series of 24 patients with dic(9;20)-positive BCP ALL diagnosed 1996-2006, constituting 1.3% of the BCP ALL, as well as 47 childhood cases from the literature. Consistent immunophenotypic features of the Nordic cases included positivity for HLA-DR, CD10, CD19, CD20, and CD22 and negativity for T-cell and myeloid markers; no detailed immunophenotypes were reported for the previously published cases. In the entire cohort of 71 cases, the modal chromosome distribution was 45 (62%), 46 (21%), 47 (7%), 48 (4%), 49 (3%), 44 (1%), and 50 (1%). Additional changes were present in 63%, the most frequent of which were homozygous loss of CDKN2A (33%) and gains of chromosomes 21 (28%) and X (10%). The median patient age was 3 years, the female/male ratio was 2.0, the median white blood cell count was 24 x 10(9)/l, 11% had central nervous system involvement, and 5% had a mediastinal mass at diagnosis. Risk group stratification was nonstandard risk in 79%. The event-free survival and overall survival at 5 years for the 24 Nordic cases was 0.62 and 0.82, respectively. Thus, although relapses are quite common, postrelapse treatment of many patients is successful.
authors.affiliation: Department of Clinical Sciences, Pediatrics, University of Umeå, Umeå, Sweden. ann.nordgren@ki.se
authors.forename: Erik
authors.initials: E
authors.lastname: Forestier
authors.forename: Fredrika
authors.initials: F
authors.lastname: Gauffin
authors.forename: Mette K
authors.initials: MK
authors.lastname: Andersen
authors.forename: Kirsi
authors.initials: K
authors.lastname: Autio
authors.forename: Georg
authors.initials: G
authors.lastname: Borgström
authors.forename: Irina
authors.initials: I
authors.lastname: Golovleva
authors.forename: Britt
authors.initials: B
authors.lastname: Gustafsson
authors.forename: Sverre
authors.initials: S
authors.lastname: Heim
authors.forename: Kristina
authors.initials: K
authors.lastname: Heinonen
authors.forename: Mats
authors.initials: M
authors.lastname: Heyman
authors.forename: Randi
authors.initials: R
authors.lastname: Hovland
authors.forename: Johann H
authors.initials: JH
authors.lastname: Johannsson
authors.forename: Gitte
authors.initials: G
authors.lastname: Kerndrup
authors.forename: Richard
authors.initials: R
authors.lastname: Rosenquist
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Schoumans
authors.forename: Birgitta
authors.initials: B
authors.lastname: Swolin
authors.forename: Bertil
authors.initials: B
authors.lastname: Johansson
authors.forename: Ann
authors.initials: A
authors.lastname: Nordgren
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002890:Chromosomes, Human, Pair 20 / Q000235:genetics*; D002899:Chromosomes, Human, Pair 9 / Q000235:genetics*; D003582:Cytogenetics; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007621:Karyotyping; D015448:Leukemia, B-Cell / Q000235:genetics*; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D012537:Scandinavian and Nordic Countries; D014178:Translocation, Genetic