Immunohistochemical Detections of EGFR Mutations in NSCLC

In recent years, it has been well known that non-small cell lung cancer (NSCLC) patients with mutations of epidermal growth factor receptor (EGFR) response better to EGFR-tyrosine kinase inhibitor treatment. Although DNA-based assays (e.g. DNA sequencing) are the most frequently used and a relatively reliable method to detect EGFR mutations, they are complex, time-consuming and relatively expensive for routine use in clinical laboratories, besides they require high quality tumor samples. In contrast, the immunohistochemistry (IHC) methods make up fully for the above shortcomings and can serve as screening tests for EGFR mutations. However, there are many factors that can influence the results of IHC methods, such as different staining procedures, different antigen retrieval solutions and different sets of criteria, etc. Thus the IHC methods for detecting EGFR mutations have not been widely used in clinic and only in the research stage. This article reviews the use of IHC methods by different researchers and further discusses how to make the IHC methods work best for the detection of EGFR mutations