Figure 2. Kaplan–Meier curves of progression-free survival (PFS) of elderly patients treated with afatinib, erlotinib, or gefitinib. (A) Overall age ≥65 years; (B) age 65–74 years; (C) age 75–84 years; and (D) age ≥85 years. Abbreviations: TKI, tyrosine kinase inhibitor; CI, confidence interval.