title: Determination of EGFR status in gliomas: usefulness of immunohistochemistry and fluorescent in situ hybridization.
abstract: Epidermal growth factor receptor (EGFR) is produced during the molecular pathogenesis of glioma, and new anti-EGFR molecules are available for therapeutics. Consequently, analyses of the EGFR gene and protein are frequently used for glioma characterization. We compare the accuracy and the usefulness of 2 currently used techniques for histologic classification of gliomas. Fluorescent in situ hybridization (FISH) and immunohistochemistry (IHC) techniques were used to assess EGFR gene amplification and protein abundance in a series of 35 gliomas, including World Health Organization (WHO) grade I, II, and III astrocytomas (AI, AII, AIII), grade II and III tumors with oligodendroglial component (OII, OIII) and grade IV glioblastomas (GBs). EGFR gene amplification was found in one-third of the tumors studied. It was frequent in GB and OIII but was never found in AI, AII, AIII, and OII tumors. IHC and FISH provided similar findings for grade of tumor, despite the fact that, in contrast to the FISH gene amplification, EGFR protein was overexpressed in AIII and in GB. EGFR gene amplification was never observed in tumors not containing EGFR protein: therefore FISH is unnecessary when IHC shows no EGFR protein expression. EGFR gene amplification seems to be restricted to high-grade tumors, WHO grade IV astrocytomas, and grade III oligodendroglial tumors.
authors.affiliation: Department of Pathology, CHU Dupuytren, Limoges, France.
authors.forename: Angélique
authors.initials: A
authors.lastname: Guillaudeau
authors.forename: Karine
authors.initials: K
authors.lastname: Durand
authors.forename: Isabelle
authors.initials: I
authors.lastname: Pommepuy
authors.forename: Sandrine
authors.initials: S
authors.lastname: Robert
authors.forename: Alain
authors.initials: A
authors.lastname: Chaunavel
authors.forename: Sylvain
authors.initials: S
authors.lastname: Lacorre
authors.forename: Rafaël
authors.initials: R
authors.lastname: DeArmas
authors.forename: Sylvie
authors.initials: S
authors.lastname: Bourtoumieux
authors.forename: Mounira
authors.initials: M
authors.lastname: El Demery
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Moreau
authors.forename: François
authors.initials: F
authors.lastname: Labrousse
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005784:Gene Amplification; D005910:Glioma / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D066246:ErbB Receptors