EGFR and cancer: The following variants were included in the multivariate Cox proportional hazards regression model: age (≥65, <65), pathology (adenocarcinoma, non-adenocarcinoma), weight loss (<5 %, ≥5 %), smoking status (never a smoker, smoker), family history of cancer (yes, no), Eastern Cooperative Oncology Group performance status (0–1, ≥2), line of EGFR-TKI therapy (first line, second line, or further), EGFR-TKI (gefitinib, erlotinib), and dynamic types of plasma L858R (group A, group S).