EGFR and lung cancer: According to the variety of salvage surgery series for lung cancer that has been reported thus far, the patient characteristics have been stratified using pretreatment procedures, i.e. definitive chemoradiotherapy, targeted therapy using epidermal growth factor receptor–tyrosine kinase inhibitor (EGFR–TKI), high-dose stereotactic body radiation therapy or carbon ion therapy (CIT) and proton beam therapy (PBT) [10–12].