Table 3 Summary of DFS and OS in patients with unexpected small cell lung cancer

Age(years)

 ≥ 60

69 (57.5)

1.53 (0,95–2.47)

16

2.19 (1.24–3.86)

32

 < 60

51 (42.5)

1

52

1

52

Gender

Male

93 (77.5)

0.98 (0.57–1.69)

23

1.13 (0.58–2.18)

64

Female

27 (22.5)

1

15

1

51

Symptom

Yes

48 (40.0)

0.95 (0.59–1.51)

18

0.81 (0.48–1.38)

70

None

72 (60.0)

1

20

1

49

Smoking history

Yes

79 (65.8)

0.91 (0.57–1.46)

23

0.88 (0.51–1.52)

64

None

4 1(34.2)

1

15

1

46

Tumor location

Central lesion

28 (23.3)

1.07 (0.63–1.80)

17

1.02 (0.56–1.84)

64

Peripheral lesion

92 (76.7)

1

21

1

48

Surgical approach

Open

52 (43.3)

0.75 (0.46–1.22)

48

0.43 (0.25–0.75)

108

VATS

68 (56.7)

1

15

1

29

Type of operation

Lobectomy and pneumonectomy

106(88.3)

0.53 (0.27–1.03)

23

0.51 (0.25–1.04)

64

Sublobectomy

14(11.7)

1

7

1

26

Number of lymph nodes dissected

≧15

39 (32.5)

0.80 (0.48–1.33)

52

0.84 (0.47–1.53)

64

 < 15

81 (67.5)

1

16

1

49

N staging

N0

58(50)

1

48

1

108

N1

26(22.4)

1.08 (0.58–2.02)

43

1.21 (0.65–2.58)

49

N2

32(27.6)

1.72 (0.99–2.97)

13

1.75 (0.94–3.25)

34

TNM staging

Stage I

42 (35)

0.45 (0.23–1.86)

60

0.45 (0.23–1.86)

89

Stage II and IIIA

78 (65)

1

15

1

51

Vascular tumor thrombus

Yes

21 (17.5)

0.83 (0.42–1.62)

23

3.12 (1.59–4.25)

38

None

99 (82.5)

1

20

1

64

Histology

Pure SCLC

109 (90.8)

1.18 (0.47–2.94)

18

1.5 (0.47–4.8)

49

Mixed SCLC

11 (9.2)

1

61

1

55

Postoperative radiotherapy

Yes

42 (34.5)

0.88 (0.55–1.43)

23

1.15 (0.68–1.97)

29

None

78 (65.5)

1

18

1

64