Table 1 Clinical characteristics of patients with different EGFR mutation status in training set and testing set

N

161

243

41

70

Age (years)

64.83 (9.11)

63.65 (9.22)

0.210

64.22 (8.75)

63.19 (9.48)

0.570

Gender

 < 0.001

0.021

 Female

51 (31.7%)

162 (66.7%)

13 (31.7%)

38 (54.3%)

 Male

110 (68.3%)

81 (33.3%)

28 (68.3%)

32 (45.7%)

Smoking history

87 (54.0%)

54 (22.2%)

 < 0.001

18 (43.9%)

16 (22.9%)

0.020

Nodule type

 < 0.001

0.037

 Solidity

128 (79.5%)

147 (60.5%)

32 (78.0%)

41 (57.6%)

 Sub-solidity

33 (20.5%)

96 (39.5%)

9 (22.0%)

29 (42.4%)

Nodule location

0.645

0.696

 Top right

47 (29.2%)

81 (33.3%)

10 (24.4%)

21 (30.0%)

 Middle right

6 (3.7%)

14 (5.8%)

4 (9.8%)

8 (11.4%)

 Lower right

34 (21.2%)

50 (20.6%)

12 (29.2%)

14 (20.0%)

 Top left

44 (27.3%)

63 (25.9%)

9 (22.0%)

20 (28.6%)

 Lower left

30 (18.6%)

35 (14.4%)

6 (14.6%)

7 (10.0%)

Tumor long axis (mm)

32.10 (20.70–47.20)

25.60 (20.30–37.65)

0.002

40.70 (29.50–49.50)

29.40 (23.70–38.60)

0.008

Tumor short axis (mm)

23.20 (14.60–33.20)

19.00 (14.30–27.65)

0.015

29.60 (24.10–33.40)

22.35 (16.20–28.45)

0.008

Clinical stage

0.005

0.378

 I

52 (32.3%)

125 (51.4%)

8 (19.5%)

24 (34.3%)

 II

12 (7.5%)

3 (1.2%)

4 (9.8%)

5 (7.1%)

 III

33 (20.5%)

35 (14.4%)

8 (19.5%)

9 (12.9%)

 IV

64 (39.8%)

80 (32.9%)

21 (51.2%)

32 (45.7%)

CEA (ng/ml)

5.24 (2.61–15.61)

3.23 (1.60–12.25)

0.016

5.08 (2.42–13.39)

5.58 (2.24–19.84)

0.781

CYFRA 21–1 (ng/ml)

3.58 (2.42–6.20)

3.23 (2.17–5.34)

0.084

4.36 (3.24–6.43)

3.73 (2.58–6.90)

0.313

NSE (ng/ml)

15.10 (11.79–20.28)

14.75 (12.04–20.38)

0.988

15.81 (13.07–20.55)

14.97 (12.14–18.64)

0.281

SCC-Ag (ng/ml)

1.01 (0.72–1.51)

0.78 (0.56–1.01)

 < 0.001

0.89 (0.72–1.29)

0.83 (0.56–1.18)

0.350

SUV_max (ng/ml)

13.03(6.27–18.21)

10.14(3.44–17.51)

0.005

15.60(8.51–20.67)

13.62(5.50–17.98)

0.139