EGFR and non-small cell lung carcinoma: Per the 2015 National Comprehensive Cancer Network (NCCN) guidelines 1, routine EGFR mutation testing is recommended in NSCLC of adenocarcinoma, large cell, or unknown histology, but not in squamous cell carcinoma (except in never smokers and mixed histology or small biopsy specimens) given its rarity in this subtype.