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Updated: Apr 25, 2026
Evaluation of Biomarkers in Glioma by Immunohistochemistry on Paraffin-Embedded 3D Glioma Neurosphere Cultures
Published on: January 9, 2019
EGFR and EGFRvIII analysis in glioblastoma as therapeutic biomarkers
Claire Faulkner1, Abigail Palmer1, Hannah Williams2
1a Bristol Genetics Laboratory, Southmead Hospital, North Bristol NHS Trust , Bristol , UK.
Introduction:
EGFR and EGFRvIII analysis is of current interest because of new EGFRvIII vaccine trials opened in the UK. EGFR activation promotes cellular proliferation via activation of MAPK and PI3K-Akt pathways. EGFRvIII is the most common variant resulting from an in-frame deletion of 801bp, leading to constitutively active EGFR.
Method:
51 glioblastoma samples from a cohort of 50 patients were tested for EGFR amplification by FISH and immunohistochemistry and EGFRvIII expression by reverse-transcriptase PCR (RT-PCR), and immunohistochemistry. EGFR and EGFRvIII expression was compared with Overall Survival in the cohort.
Results:
Overall 22/51 samples (43%) were positive for EGFR, 16/51 (31%) were positive for EGFRvIII and 13/51 (25%) were positive for both. 9/51 cases (18%) were positive for EGFR alone, and 3/51 (6%) were positive for EGFRvIII alone. Of the EGFR positive cases, 22/51 (43%) were positive by FISH, 24/51 (47%) were positive by IHC and 2/51 (4%) were discrepant between methods (positive by IHC but non-amplified by FISH). Of the EGFRvIII positive cases, 16/51 (31%) were positive by RT-PCR, 17/51 (33%) were positive by IHC and 1/51 (2%) sample was discrepant (positive by IHC but not by RT-PCR). Neither EGFRvIII or EGFR are predictive of overall survival in this cohort.
Conclusion:
In our cohort, 25/51 (49%) of GBM showed EGFR alterations, including 16/51 (31%) with EGFRvIII. There was high concordance between IHC and FISH (96%) and IHC and RT-PCR (98%) as diagnostic methods. Neither EGFR or EGFRvIII is predictive of overall survival in this cohort. These results are key for selecting patients for novel individualised anti-EGFR therapies.
