In the univariate analysis of OS, age (≤60 vs. >60 years), smoking status, pathological type (adenocarcinoma vs. squamous cell carcinoma), EGFR mutations status (exon 19 deletion vs. exon 21 L858R), different durations of EGFR-TKI therapy, and chemotherapy prior to the adjuvant EGFR-TKI therapy were not associated with OS. Here, EGFR is linked to squamous cell carcinoma.