Table 2 Characteristics comparison of patients with PSN and SN stratified by tumor size

Age

57.76 ± 10.58

53.46 ± 11.75

0.018

61.11 ± 9.14

59.76 ± 10.16

0.069

63.27 ± 8.15

62.41 ± 10.32

0.473

Gender (female%)

358 (66.9%)

24 (64.9%)

0.940

196 (58.9%)

191 (55.7%)

0.450

55 (61.1%)

132 (46.3%)

0.020

Smoking (Ever%)

62 (11.6%)

5 (13.5%)

0.930

52 (15.6%)

74 (21.6%)

0.059

17 (18.9%)

77 (27.0%)

0.158

ASA score

0.595

0.384

0.588

 I

207 (38.7%)

17 (45.9%)

117 (35.1%)

122 (35.6%)

26 (28.9%)

81 (28.4%)

 II

292 (54.6%)

17 (45.9%)

189 (56.8%)

183 (53.4%)

52 (57.8%)

153 (53.7%)

 III

36 (6.7%)

3 (8.1%)

27 (8.1%)

38 (11.1%)

12 (13.3%)

51 (17.9%)

Hypertension

156 (29.2%)

6 (16.2%)

0.133

118 (35.4%)

116 (33.8%)

0.718

31 (34.4%)

104 (36.5%)

0.821

Diabetes

43 (8.0%)

2 (5.4%)

0.795

29 (8.7%)

43 (12.5%)

0.137

11 (12.2%)

44 (15.4%)

0.561

Coronary heart disease

22 (4.1%)

2 (5.4%)

1

19 (5.7%)

21 (6.1%)

0.947

7 (7.8%)

25 (8.8%)

0.938

Chronic respiratory diseases

18 (3.4%)

0

0.518

13 (3.9%)

12 (3.5%)

0.940

3 (3.3%)

11 (3.9%)

1

Tumor location

0.075

0.018

0.071

 RUL

196 (36.6%)

15 (40.5%)

124 (37.2%)

100 (29.2%)

36 (40.0%)

70 (24.6%)

 RML

43 (8.0%)

3 (8.1%)

24 (7.2%)

27 (7.9%)

8 (8.9%)

24 (8.4%)

 RLL

76 (14.2%)

3 (8.1%)

52 (15.6%)

61 (17.8%)

14 (15.6%)

53 (18.6%)

 LUL

130 (24.3%)

4 (10.8%)

93 (27.9%)

85 (24.8%)

18 (20.0%)

79 (27.7%)

 LLL

90 (16.8%)

12 (32.4%)

40 (12.0%)

70 (20.4%)

14 (15.6%)

59 (20.7%)

Total tumor size (cm)

1.65 ± 0.66

0.82 ± 0.16

< 0.001

2.34 ± 0.68

1.60 ± 0.28

< 0.001

3.40 ± 0.89

2.52 ± 0.28

< 0.001

Solid size (cm)

0.59 ± 0.25

0.82 ± 0.16

< 0.001

1.44 ± 0.28

1.60 ± 0.28

< 0.001

2.42 ± 0.27

2.52 ± 0.28

0.002

CTR

0.39 ± 0.18

1

< 0.001

0.65 ± 0.16

1

< 0.001

0.74 ± 0.14

1

< 0.001

Surgery (Lobectomy%)

306 (57.2%)

15 (40.5%)

0.071

273 (82.0%)

284 (82.8%)

0.859

85 (94.4%)

269 (94.4%)

1

Pathological size (cm)

1.32 ± 0.54

0.85 ± 0.30

< 0.001

1.80 ± 0.61

1.53 ± 0.49

< 0.001

2.50 ± 0.91

2.35 ± 0.61

0.087

Histological types

< 0.001

< 0.001

0.007

 ADC

532 (99.4%)

34 (91.9%)

330 (99.1%)

314 (91.5%)

89 (98.9%)

251 (88.1%)

 other

3 (0.6%)

2 (5.4%)

2 (0.6%)

15 (4.4%)

1 (1.1%)

8 (2.8%)

 SCC

0

1 (2.7%)

1 (0.3%)

14 (4.1%)

0

26 (9.1%)

Evaluated lymph nodes

10.57 ± 3.97

10.32 ± 4.12

0.716

11.82 ± 4.52

11.75 ± 4.86

0.839

14.92 ± 5.81

12.75 ± 4.96

0.001

Lymph node metastasis

2 (0.4%)

0

1

13 (3.9%)

54 (15.7%)

< 0.001

11 (12.2%)

90 (31.6%)

0.001

N1 station metastasis

1 (0.2%)

0

1

11 (3.3%)

41 (12.0%)

< 0.001

8 (8.9%)

77 (27.0%)

0.001

N2 station metastasis

1 (0.2%)

0

1

7 (2.1%)

35 (10.2%)

< 0.001

7 (7.8%)

58 (20.4%)

0.01

Skip lymph node metastasis

1 (0.2%)

0

1

2 (0.6%)

13 (3.8%)

0.011

3 (3.3%)

13 (4.6%)

0.839

Pleural invasion

23 (4.3%)

0

0.393

30 (9.0%)

56 (16.3%)

0.006

18 (20.0%)

84 (29.5%)

0.104

Bronchi invasion

1 (0.2%)

0

1

2 (0.6%)

16 (4.7%)

0.002

3 (3.3%)

28 (9.8%)

0.084

Solid component

18 (3.4%)

0

0.507

21 (6.6%)

68 (22.4%)

< 0.001

14 (15.6%)

63 (22.2%)

0.228

Micropapillary component

12 (2.3%)

1 (2.7%)

1

20 (6.2%)

41 (13.5%)

0.004

6 (6.7%)

45 (15.8%)

0.042

Ki-67 expression

10.0 (5–15)

5.0 (4.0-22.5)

0.898

10.0 (5–20)

17.0 (10-42.5)

< 0.001

17.0 (10-22.5)

30.0 (17–50)

< 0.001

EGFR mutation

179 (75.2%)

4 (36.4%)

0.012

125 (82.2%)

82 (61.7%)

< 0.001

38 (80.9%)

74 (63.2%)

0.045

ALK fusion

1

0.077

1

 No

112 (98.2%)

6 (100.0%)

54 (100.0%)

52 (91.2%)

15 (100.0%)

38 (97.4%)

 Yes

2 (1.8%)

0

0

5 (8.8%)

0

1 (2.6%)

ROS1 fusion

1

0.475

1

 No

113 (100.0%)

6 (100.0%)

53 (100.0%)

51 (96.2%)

15 (100.0%)

38 (100.0%)

 Yes

0

0

0

2 (3.8%)

0

0

Adjuvant therapy

27 (5.0%)

1 (2.7%)

0.806

38 (11.4%)

77 (22.4%)

< 0.001

42 (46.7%)

163 (57.2%)

0.104