Table 1 Baseline clinical characteristics of the study population

Median Age, years (range)

61 (36–80)

  ≥ 65

30 (30.3%)

  < 65

69 (69.7%)

Gender

  Male

37 (37.4%)

  Female

62 (62.6%)

Smoking status

  Ever

27 (27.3%)

  Never

72 (72.7%)

Histology

  ADC

98 (99.0%)

  SCC

1 (1.0%)

EGFR Mutant

  19del

62 (62.6%)

  L858R

37 (37.4%)

CNS metastasis

  Yes

16 (16.2%)

  No

83 (83.8%)

Liver metastasis

  Yes

11 (11.1%)

  No

88 (88.9%)

Bone metastasis

  Yes

47 (47.5%)

  No

52 (52.5%)

Median PFS of 1^st-generation EGFR-TKI, months (95%CI)

12.43 (3.2–51.8)

  ≥ 12 months

53 (53.5%)

  < 12 months

46 (46.5%)

BOR of 1^st-generation EGFR-TKI

  SD

24 (24.2%)

  PR

75 (75.8%)

Pleural effusion

  With

45 (45.5%)

  Without

54 (54.5%)