EGFR mutation testing in non-small cell lung cancer (NSCLC)

Lung carcinoma is subdivided into small cell carcinoma and non-small cell carcinoma (NSCLC). NSCLC is heterogeneous group of carcinomas and accounts for 70-80% of lung cancer. NSCLC is further divided into adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. Activating somatic mutations of the tyrosine kinase domain of epidermal growth factor receptor (EGFR) have recently been characterized in a subset of patients with non-small cell lung cancer (NSCLC). These mutations involve exons 18, 19, 20 and 21. Patients harboring these mutations in their tumors show good response to EGFR tyrosine kinase inhibitors (EGFR-TKIs). The aim of this manuscript is to provide an overview of EGFR mutations in NSCLC as well as to briefly discuss sample requirements and testing guidelines for EGFR mutation.