Epidermal growth factor receptor (EGFR) status in chordoma

Chordoma is a rare tumour arising from the embryonal remnants of a notochord occurring most commonly in the sacrococcygeal as well as head and neck locations. Current treatment includes surgery and/or proton beam radiotherapy. In several cases especially in the head and neck location, surgery is not advised. Proton beam therapy is not always effective enough to eradicate the tumour. Additional modes of therapy are needed. One of the current therapeutic approaches in various tumours is targeted therapy and one of the targets is EGFR. The aim of this study was to evaluate EGFR expression and EGFR gene status of chordoma. Twenty-one cases of chordoma were retrieved from the in-house and consultation files of the Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology in Warsaw. Immunohistochemistry with an anti-EGFR antibody and FISH was performed on slides obtained from representative archival paraffin blocks. In our study 81% of cases of chordoma showed low to high EGFR expression in immunohistochemistry. In six cases (26.6%) the FISH results for EGFR were classified as positive (an average EGFR copy number ł 4 per cell). There was one case of chromosome 7 aneuploidy reported.