Differential Expression of EGFR Protein by Immunohistochemical Staining Methods and the Relationship Between the Degree of EGFR Protein Expression and EGFR Gene Mutation

면역조직화학적 염색 방법에 따른 상피세포 성장 수용체 단백(EGFR)의 발현정도의 차이 및 EGFR의 발현정도와 EGFR 유전자의 돌연변이와의 상관관계에 대한 고찰

In the last 5 years the Epidermal Growth Factor Receptor (EGFR) has emerged as one of the most important targets for drug development in oncology. Monoclonal antibodies targeting the external domain of EGFR have been shown to have clinical benefits in colorectal and head and neck cancer when combined with chemotherapy and/or radiation. Also the targeting of the epithelial growth factor receptor (EGFR) kinase domain using the closely related inhibitors gefitinib and erlotinib has generally been ineffective against solid tumors, many of which over express the receptor. We found that there were some differential expressions according to primary antibodies of the EGFR protein which being used as one of the histological tumor markers for non-small cell lung cancer (NSCLC). We also found that there are some differential expressions according to antibodies, the pH of the antigen retrieval (AR) buffer solutions and kinds of enzymes. There were some differential expressions according to the secondary antibodies and the detection systems. We analyzed the correlations between the immunohistochemical expressions of the EGFR protein and the gene mutations of the EGFR. The differences between automatic stainers and manual staining methods were also evaluated.