Analysis of EGFRvIII and EGFR overexpression in glioma and its prognostic significance

Background

The clinical significance of EGFRvIII and EGFR wild type expression in glioblastoma multiforme (GBM) with correlation to clinical outcome have not been consistent. We sought to evaluate the clinical significance of EGFRvIII status and the EGFR overexpression in GBM among the Indian population, where potential targeted therapy may be the only hope.

Methods

A single centre, non-randomized, retrospective study with a prospective arm was done. All patients were treated at the Amrita Institute Of Medical Sciences, Kochi between Jan 2014 and August 2015. 40 patients were included; being the first of its kind in the Indian context the study was undertaken as a pilot.

Results

Results show expression of EGFRvIII had no correlation with the clinical outcome, OS 17.5 months vs 16.7 months (p = 0.920), PFS 11months vs 8.8months (p = 0.520). However a significant number of patients expressed EGFRvIII (58%). Surprisingly, the majority of patients expressed the EGFR wild type, and EGFR exon 19 (57%) over-expression had a significantly negative impact on the clinical outcome, with an OS of 7.3 months vs 15.4 months and PFS 7.3months vs 13months (p = 0.001).

Conclusions

We found that a high percentage of GBM exhibit EGFR overexpression and amplification, as did a significant proportion expressing EGFRvIII. Our results represent a step forward for the identification of GBM patients in the Indian scenario who could respond to specific therapies targeting EGFR. This requires confirmation in independent larger data sets.

Clinical trial identification

Legal entity responsible for the study

Amrita Institute of Medical Sciences

Funding

Amrita Institute of Medical Sciences

Disclosure

All authors have declared no conflicts of interest.