Table 1 Clinical characteristics and treatment responses for all patients

N

179

102

77

Age (year)

64.3 ± 9.4

65.7 ± 9.3

62.4 ± 9.3

0.0199

Age group:

0.0212

  < 65 years old

80 (45%)

38 (37%)

42 (55%)

  ≥ 65 years old

99 (55%)

64 (63%)

35 (45%)

Sex

0.0014

 Female

110 (61%)

73 (72%)

37 (48%)

 Male

69 (39%)

29 (28%)

40 (52%)

Smoking history:

0.9349

 Never smoker

140 (78%)

80 (78%)

60 (78%)

 Ever smoker

39 (22%)

22 (22%)

17 (22%)

Height (cm)

160 ± 8

159.1 ± 7.7

161.2 ± 8.4

0.0905

Weight (kg)

60 ± 11.6

58.2 ± 12.5

62.4 ± 9.9

0.0140

Body mass index (kg/m²)

23.3 ± 3.6

22.8 ± 3.7

24 ± 3.4

0.0339

Body surface area (m²)

1.6 ± 0.2

1.6 ± 0.2

1.7 ± 0.2

0.0078

Serum creatinine level

0.8 ± 0.3

0.8 ± 0.3

0.8 ± 0.3

0.4561

eCCr-CG (mL/min) ^a

77.1 ± 26.8

73.7 ± 25.9

81.5 ± 27.5

0.0566

eGFR-MDRD (mL/min/1.73m²) ^b

88.8 ± 27

88 ± 26.8

89.8 ± 27.4

0.6628

Serum albumin (mg/dL)

4.0 ± 0.5

4.0 ± 0.4

4.1 ± 0.5

0.2751

Serum glutamic oxaloacetic transaminase (U/L)

29.6 ± 22.8

31.4 ± 28.7

27.3 ± 10.4

0.1835

Serum glutamic pyruvic transaminase (U/L)

26.5 ± 25.1

26.7 ± 28.5

26.3 ± 20

0.9178

Hepatitis B: ^c

0.4999

 Negative

147 (84%)

86 (85%)

61 (81%)

 Positive

29 (16%)

15 (15%)

14 (19%)

Hepatitis C: ^c

0.0370

 Negative

165 (94%)

98 (97%)

67 (89%)

 Positive

11 (6%)

3 (3%)

8 (11%)

Old tuberculosis:

0.8901

 Negative

174 (97%)

99 (97%)

75 (97%)

 Positive

5 (3%)

3 (3%)

2 (3%)

Family history:

0.0859

 Negative

168 (94%)

93 (91%)

75 (97%)

 Positive

11 (6%)

9 (9%)

2 (3%)

Performance status while starting afatinib:

0.1024

 ECOG ≤1

146 (82%)

79 (77%)

67 (87%)

 ECOG ≥2

33 (18%)

23 (23%)

10 (13%)

TTF-1 stain: ^c

0.8901

 Positive

170 (100%)

99 (100%)

71 (100%)

PDL-1 stain: ^c

0.4732

 Absence

33 (38%)

16 (34%)

17 (41%)

 Presence

55 (63%)

31 (66%)

24 (59%)

EGFR gene mutation site: ^d

 Exon 19

95 (53%)

60 (59%)

35 (45%)

0.0760

 Exon 21

85 (47%)

42 (41%)

43 (56%)

0.0517

TNM staging:

 N2–3

112 (63%)

67 (66%)

45 (58%)

0.3214

 M1a-c

179 (100%)

102 (100%)

77 (100%)

0.5136

Number of metastatic sites/organs (1–2 vs. > 2)

0.2360

 1 site

64 (36%)

41 (40%)

23 (30%)

 2 sites

69 (39%)

39 (38%)

30 (39%)

  ≥ 3 sites

46 (26%)

22 (22%)

24 (31%)

 Brain

53 (30%)

21 (21%)

32 (42%)

0.0023

 Lung

79 (44%)

40 (39%)

39 (51%)

0.1272

 Pleura (or with pleural effusion)

80 (45%)

47 (46%)

33 (43%)

0.6678

 Bone

99 (55%)

59 (58%)

40 (52%)

0.4322

 Liver

22 (12%)

15 (15%)

7 (9%)

0.2573

 Adrenal

16 (9%)

8 (8%)

8 (10%)

0.5544

 Other sites

11 (6%)

5 (5%)

6 (8%)

0.4253