Aim: The aim of this study was to assess both the epidermal growth factor receptor (EGFR) protein expression by immunohistochemistry and the EGFR gene amplification by fluorescence in situ hybridization in meningiomas of different grade, in order to evaluate their possible role in the development of the disease. EGFR protein belongs to the family of tyrosine kinase growth factor receptors, which also includes HER2, HER3 and HER4. Elevated expression or activity of EGFR has been reported in several cancers, including brain tumours. EGFR activation can enhance the malignant potential of epithelial tissues.
Methods: We investigated whether there was a difference in the EGFR protein expression and the EGFR gene amplification between the so called de novo malignant meningiomas and recurrent meningiomas with or without malignant progression from a previously lower grade tumor. Our goal was to evaluate if EGFR expression was a useful marker to select patients affected by meningioma with a major risk of recurrences. We also assessed the prognostic value of the EGFR expression on overall survival.
Results: Progression from benign meningiomas to atypical or anaplastic meningiomas correlated with an increase in the expression of EGFR protein. Our study shows that EGFR immunostaining in meningiomas directly correlates to the tumor's grade. The EGFR expression did not correlate with the overall survival and the recurrence-free survival of the patients affected by meningioma (de novo, recurrent and progressed).
Conclusion: We submit that the EGFR expression is not a useful prognostic element to identify patients with a major risk of meningioma recurrence.