Fig. 1

Brain-metastasis-free survival analysis according to various risk factors. a Gender (male vs female, p = 0.25), b Age (≤60 vs > 60, p = 0.006), c Stage at diagnosis (p = 0.002), d T status at diagnosis (T1/2 vs T3/4, p = 0.009), e N status at diagnosis (N0/1 vs N2/3, p < 0.001), f EGFR status (wild-type vs sensitive mutation, p = 0.018), g Histology (adenocarcinoma vs non-adenocarcinoma, p = 0.02), h Smoking status (never smoker vs current smoker, p = 0.69)