Figure 2.

Kaplan–Meier plot of survival times stratified by the cumulative smoking dose (13 pack‐years [PY]). (a) Overall survival of patients treated with gefitinib. (b) Progression‐free survival of patients treated gefitinib. MPFS, median progression‐free survival time; MST, median survival time. P‐values were calculated using the log‐rank test.