Relationship between EGFR overexpression and gene amplification status in central nervous system gliomas.
OBJECTIVE
To correlate epidermal growth factor receptor (EGFR) protein overexpression, as assessed by immunohistochemistry, with EGFR gene amplification determined by fluorescence in situ hybridization in a series of gliomas.


METHODS
Forty-seven central nervous system gliomas, including 34 cases of glioblastoma multiforme, 3 oligodendrogliomas, 4 juvenile pilocytic astrocytomas and 5 low grade astrocytomas, were obtained from the files of the University of Utah Pathology Department. In each case a representative paraffin block was selected, and EGFR protein expression was quantified using immunohistochemistry. EGFR gene amplification status was determined by fluorescence in situ hybridization.


RESULTS
EGFR protein overexpression was detected in 9 cases of glioblastoma multiforme. EGFR gene amplification was present in 7 of these cases. Both nonamplified glioblastomas demonstrated only 2+ overexpression of EGFR protein. None of the low grade, pilocytic or anaplastic astrocytomas demonstrated either EGFR protein overexpression or gene amplification.


CONCLUSIONS
EGFR protein overexpression is closely associated with gene amplification. Seventy-eight percent of cases showing protein overexpression demonstrated gene amplification. All cases of central nervous system neoplasms showing protein overexpression but lacking gene amplification were associated with only 2+ protein overexpression. All central nervous system neoplasms demonstrating gene amplification and/or overexpression were high grade neoplasms.
Tripp
Sheryl R
SR
Associated Regional and University Pathologists Institute for Clinical and Experimental Pathology, LLC, Salt Lake City, Utah 84108, USA. trippsr@aruplab.com
Willmore-Payne
Carlynn
C
Layfield
Lester J
LJ
D000328:Adult; D016543:Central Nervous System Neoplasms / Q000235:genetics*; D066246:ErbB Receptors / Q000235:genetics* / Q000378:metabolism; D005784:Gene Amplification; D005910:Glioma / Q000235:genetics*; D006801:Humans; D015854:Up-Regulation
D066246:ErbB Receptors