EGFR and neoplasm: According to the results of the tumor tissue EGFR analysis, twenty patients (64.5%) had Del 19 mutation, six patients (19.4%) had L858R mutation, one (3.2%) had both L858R and T790M mutations and four (12.9%) had other mutations (G719S+L833V, L861Q, L858M, G719C, and S768I).