title: Loss of chromosome 1p/19q in oligodendroglial tumors: refinement of chromosomal critical regions and evaluation of internexin immunostaining as a surrogate marker.
abstract: Loss of chromosome 1p/19q in oligodendrogliomas represents a powerful predictor of good prognosis. Expression of internexin (INA), a neuronal specific intermediate filament protein, has recently been proposed as a surrogate marker for 1p/19q deletion based on the high degree of correlation between both parameters in oligodendrogliomas. The aim of this study was to assess further the diagnostic utility of INA expression in a set of genetically well-characterized oligodendrogliomas. On the basis of a conservative approach for copy number determination, using both comparative genomic hybridization and fluorescent in situ hybridization, INA expression as a surrogate marker for 1p/19q loss had both reduced specificity (80%) and sensitivity (79%) compared with respective values of 86% and 96% reported in the previous report. The histologic interpretation and diagnostic value of INA expression in oligodendrogliomas should therefore be assessed with greater caution when compared with 1p/19q DNA copy number analysis. In addition, DNA copy number aberrations of chromosomes 10, 16, and 17 were detected exclusively in 1p/19q codeleted samples, suggesting that other regions of the genome may contribute to the 1p/19q-deleted tumor phenotype inthese samples.
authors.affiliation: The Royal College of Surgeons in Ireland, Cancer Genetics, 2nd Floor York House, York Street, Dublin, Dublin 2, Ireland. pbuckley@rcsi.ie
authors.forename: Patrick G
authors.initials: PG
authors.lastname: Buckley
authors.forename: Leah
authors.initials: L
authors.lastname: Alcock
authors.forename: Josephine
authors.initials: J
authors.lastname: Heffernan
authors.forename: Jack
authors.initials: J
authors.lastname: Woods
authors.forename: Francesca
authors.initials: F
authors.lastname: Brett
authors.forename: Raymond L
authors.initials: RL
authors.lastname: Stallings
authors.forename: Michael A
authors.initials: MA
authors.lastname: Farrell
mesh_terms: D015415:Biomarkers / Q000378:metabolism*; D002872:Chromosome Deletion; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics* / Q000378:metabolism; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics* / Q000378:metabolism; D055028:Comparative Genomic Hybridization; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007381:Intermediate Filament Proteins / Q000235:genetics / Q000378:metabolism*; D009837:Oligodendroglioma / Q000235:genetics* / Q000473:pathology
chemical_list: D015415:Biomarkers; D007381:Intermediate Filament Proteins; C046643:alpha-internexin