gms | German Medical Science

The purpose of this study was to investigate the expression level of the epidermal growth factor receptor (EGFR),the platelet derived growth factor receptor 1-alpha (PDGFR) and the vascular endothelial growth factor receptor (VEGFR) by immunohistochemistry (IHC) in recurrent human meningiomas.

We tested 12 cases of recurrent menigiomas with secondary malignization in comparison with 10 recurrent meningiomas without malignization and 8 normal control tissues from autopsy brains, containing regular leptomeninx for expression of EMA, MIB-1, EGFR, PDGFR and VEGFR by immunochemistry (IR) using the indirect peroxidase technique on tissue microarrays (TMA) of paraffin-embedded specimens. TMA samples were chosen on the basis of viewed full size slides and contained 1–5 samples per tumor with a diameter of 1.5 mm each. Staining was evaluated using a semiquantitative scoring system except for MIB-1 where percentages were calculated. Chi-square test was used for statistical evaluation.

We found EMA -IHC of varying levels in all meningiomas and in regular leptomeninges. Grade I meningiomas showed proliferation rates below 6% regardless of recurrence. High proliferation rates were associated with malignancy (up to 40% of tumor cells). Recurrent meningiomas with secondary malignization showed increasing proliferation with each recurrence. Overexpression of EGFR was associated with malignancy (p < 0.01) and increased with recurrence (median score 2.3) While PDGFR and VEGFR scores were higher in malignant tumors, the difference was not significant.

Our data demonstrate the overexpression of EGFR in association with malignancy of meningiomas. Thus, EGFR may provide a therapeutic target for the treatment of inoperable malignant meningioma.