Determination of EGFR status in gliomas: usefulness of immunohistochemistry and fluorescent in situ hybridization.
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.
Guillaudeau
Angélique
A
Department of Pathology, CHU Dupuytren, Limoges, France.
Durand
Karine
K
Pommepuy
Isabelle
I
Robert
Sandrine
S
Chaunavel
Alain
A
Lacorre
Sylvain
S
DeArmas
Rafaël
R
Bourtoumieux
Sylvie
S
El Demery
Mounira
M
Moreau
Jean-Jacques
JJ
Labrousse
François
F
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
D066246:ErbB Receptors