Table 1 The Baseline Patient Data

Age groups

 <40 years

10

8.1

5

2.2

*

 40–49 years

20

16.1

20

9.0

 50–59 years

39

31.5

76

34.1

 60–69 years

43

34.7

96

43.0

 70–79 years

12

9.7

26

11.7

Marital status

 Married

122

98.4

221

99.1

0.55

 Widowed

2

1.6

2

0.9

Educational Backgroung

 Primary School

49

39.5

88

39.5

0.80

 Junior High School

31

25.0

66

29.6

 High School/Technical secondary school

18

14.5

26

11.7

 Associate College

13

10.5

25

11.2

 University

13

10.5

18

9.1

Gender

 Male

15

12.1

99

44.4

*

 Female

109

87.9

124

55.6

Pathologic Classification

 Squmous cell cancer

9

7.3

50

22.4

*

 Adenocancer

115

92.7

173

77.6

TNM Classification

 IA1

59

47.6

22

9.9

*

 IA2

34

27.4

66

29.6

 IA3

6

4.8

46

20.6

 IB

1

0.8

16

7.2

 IIA

0

0.0

8

3.6

 IIB

8

6.5

29

13.0

 IIIA

6

4.8

23

10.3

 IIIB

0

0.0

3

1.3

 IIIC

0

0.0

0

0.0

 IVA

10

8.1

10

4.5

Smoking pack–year history

 Negative

84

67.7

111

49.8

*

 Positive

40

32.3

112

50.2

Profession

 Worker

44

35.5

36

16.1

*

 Farmer

13

10.5

29

13.0

 Staff

14

11.3

27

12.1

 Civil servant

3

2.4

2

0.9

 Teacher

7

5.6

18

8.1

 OTH

43

34.7

111

49.8

Nationality

 Han Nationality

120

96.8

223

100.0

0.06

 Manchu

1

0.8

0

0.0

 Hui Nationality

2

1.6

0

0.0

 Daur

1

0.8

0

0.0