EGFR expression variance in paired colorectal cancer primary and metastatic tumors

Background: Previous studies indicate that drugs targeting the Epidermal Growth Factor Receptor (EGFR) signaling pathways can induce objective responses, prolong time to progression and improve survival of patients with metastatic colorectal cancer (mCRC). EGFR expression in the primary tumour may not predict response to these agents and data is conflicting regarding the correlation of EGFR expression in the primary tumour with the metastatic site. In other tumour sites, the presence of EGFR mutations was associated with efficacy in a subset of patients.Objectives: The goal of this study is to correlate tumour EGFR expression between primary and liver metastatic sites, and to assess the mutational status in the EGFR kinase domain.Methods: This is a single center retrospective study of patients who underwent surgical resection of CRC, for whom paired paraffin-embedded tissue blocks of primary tumours and resected liver metastases were available. EGFR immunostaining and mutation analyses were preformed.Resu...