Table 1 Characteristics of subjects enrolled in this study

Age

59.44 ± 10.08

60.54 ± 10.53

0.034

Gender: female

609 (63.6%)

347 (52.2%)

< 0.001

Smoking

131 (13.7%)

156 (23.5%)

< 0.001

ASA score

 I

350 (36.5%)

220 (33.1%)

< 0.001

 II

533 (55.7%)

353 (53.1%)

 III

75 (7.8%)

92 (13.8%)

Hypertension

305 (31.8%)

226 (34.0%)

0.394

Diabetes

83 (8.7%)

89 (13.4%)

0.003

Coronary heart disease

48 (5.0%)

48 (7.2%)

0.081

Chronic respiratory diseases

34 (3.5%)

23 (3.5%)

1

Tumor location

0.001

 RUL

356 (37.2%)

185 (27.8%)

 RML

75 (7.8%)

54 (8.1%)

 RLL

142 (14.8%)

117 (17.6%)

 LUL

241 (25.2%)

168 (25.3%)

 LLL

144 (15.0%)

141 (21.2%)

Total tumor size (cm)

2.06 ± 0.88

1.95 ± 0.59

0.007

Solid size (cm)

1.06 ± 0.65

1.95 ± 0.59

< 0.001

CTR

0.51 ± 0.22

1.00 ± 0.00

< 0.001

Surgical procedure

< 0.001

 Sublobar

294 (30.7%)

97 (14.6%)

 Lobar

664 (69.3%)

568 (85.4%)

Pathological size (cm)

1.60 ± 0.71

1.84 ± 0.71

< 0.001

Histological types

< 0.001

 ADC

951 (99.3%)

599 (90.1%)

 SCC

1 (0.1%)

41 (6.2%)

 Others

6 (0.6%)

25 (3.8%)

Evaluated lymph nodes

11.41 ± 4.54

12.10 ± 4.90

0.004

Lymph node metastasis

26 (2.7%)

144 (21.7%)

< 0.001

N1 station metastasis

20 (2.1%)

118 (17.7%)

< 0.001

N2 station metastasis

15 (1.6%)

93 (14.0%)

< 0.001

Skip lymph node metastasis

6 (0.6%)

26 (3.9%)

< 0.001

Number of metastatic lymph node

3

3.65

0.230

Pleural invasion

71 (7.4%)

140 (21.1%)

< 0.001

Bronchi invasion

6 (0.6%)

44 (6.6%)

< 0.001

Solid component

53 (5.7%)

131 (21.0%)

< 0.001

Micropapillary component

38 (4.1%)

87 (13.9%)

< 0.001

Ki-67 expression level

12.86 ± 11.38

30.02 ± 23.57

< 0.001

EGFR mutation ^a

< 0.001

 Wild type

95 (21.7%)

101 (38.7%)

 Mutant type

342 (78.3%)

160 (61.3%)

ALK fusion ^a

 No

181 (98.9%)

96 (94.1%)

0.049

 Yes

2 (1.1%)

6 (5.9%)

ROS1 fusion ^a

 No

181 (100.0%)

95 (97.9%)

0.232

 Yes

0

2 (2.1%)

Adjuvant therapy

107 (11.2%)

241 (36.2%)

< 0.001