Table 4 Univariate Analysis of predictors for Loco-regional recurrence (LRR), distant metastasis (DM), any progression and overall survival (OS) for patients with limited stage small cell lung cancer (LS-SCLC) treated with chemoradiation, (n = 105)

Gender

 Female^a

–

–

–

–

–

–

–

–

–

–

 Male

0.75 (0.39–1.44)

0.39

0.80 (0.38–1.71)

0.57

0.70 (0.41–1.21)

0.20

0.70 (0.43–1.16)

0.17

0.50 (0.32–0.80)

0.003^c

Age (continuous)

0.97 (0.94–1.01)

0.20

0.95 (0.91–0.99)

0.04

1.00 (0.97–1.03)

0.96

0.99 (0.96–1.02)

0.56

1.01 (0.98–1.04)

0.46

Race

 White^a

–

–

–

–

–

–

–

–

–

–

 African American

0.65 (0.09–4.76)

0.67

–

0.99

1.44 (0.45–4.64)

0.54

1.22 (0.38–3.89)

0.74

1.31 (0.47–3.66)

0.61

0.37 (0.05–2.67)

0.89 (0.28–2.86)

0.71 (0.22–2.28)

1.00 (0.36–2.76)

 Other^b

0.32

0.47 (0.06–3.74)

0.46

0.84

0.60

0.99

Performance score

 0^a

–

–

–

–

–

–

–

–

–

–

 ≥1

2.00 (0.94–4.25)

0.07

1.61 (0.71–3.66)

0.25

2.92 (1.46–5.84)

0.002^c

2.90 (1.53–5.48)

0.001^c

3.05 (1.70–5.45)

< 0.001^c

Smoking history

 Current^a

–

–

–

–

–

–

–

–

–

 Former

0.71 (0.36–1.39)

0.32

–

–

1.05 (0.61–1.79)

0.87

0.99 (0.60–1.65)

0.97

1.15 (0.72–1.82)

0.56

1.92 (0.45–8.19)

0.52 (0.07–3.83)

1.16 (0.28–4.81)

0.99 (0.24–4.1)

 Never

0.38

–

–

0.52

0.84

0.99

Pack-years

1.01 (0.99–1.02)

0.21

1.00 (0.99–1.02)

0.96

1.01 (1.00–1.02)

0.11

1.01 (0.99–1.01)

0.20

1.01 (1.00–1.02)

0.12

T stage

T0–1^a

–

–

–

–

–

–

–

–

–

–

T2–4

0.66 (0.34–1.28)

0.22

0.93 (0.44–1.99)

0.85

0.64 (0.37–1.12)

0.12

0.64 (0.38–1.08)

0.09

0.67 (0.41–1.10)

0.11

N stage

N0–1^a

–

–

–

–

–

–

–

–

–

–

N2–3

5.47 (0.75–39.93)

0.09

–

–

1.64 (0.59–4.56)

0.34

2.06 (0.75–5.67)

0.16

1.35 (0.62–2.95)

0.45

Overall stage

IIIB^a

–

–

–

–

–

–

–

–

–

–

IA-IIIA

0.59 (0.28–1.25)

0.17

0.32 (0.13–0.78)

0.01^c

0.68 (0.36–1.28)

0.23

0.69 (0.39–1.22)

0.20

0.73 (0.44–1.22)

0.23

1.34

0.33 (0.12–0.94)

1.45 (0.75–2.78)

1.37 (0.73–2.55)

0.97 (0.54–1.79)

(0.61–2.95)

IIIC

0.47

0.04

0.26

0.33

0.95

Induction chemotherapy

 Yes

1.77 (0.69–4.53)

0.24

1.67 (0.58–4.80)

0.34

1.33 (0.65–2.73)

0.43

1.43 (0.73–2.82)

0.30

1.65 (0.87–3.14)

0.12

 No^a

–

–

–

–

–

–

–

–

–

Concurrent chemotherapy

 Yes

0.43 (0.17–1.11)

0.08

0.89 (0.21–3.77)

0.88

0.40 (0.18–0.90)

0.03

0.33 (0.16–0.68)

0.003^c

0.29 (0.15–0.54)

< 0.001^c

 No^a

–

–

–

–

–

–

–

–

PCI

 Yes

0.71 (0.37–1.36)

0.30

1.21 (0.53–2.74)

0.65

0.40 (0.23–0.68)

< 0.001^c

0.44 (0.27–0.73)

0.001^c

0.37 (0.23–0.59)

< 0.001^c

 No^a

–

–

–

–

–

–

–

–

–

–

Median RT dose

0.97 (0.93–1.01)

0.15

0.94 (0.90–0.99)

0.02^c

1.03 (1.00–1.06)

0.04

1.01 (0.99–1.04)

0.34

1.01 (0.99–1.04)

0.34

RT fractionation

 Daily^a

–

–

–

–

–

–

–

–

–

–

 BID

1.13 (0.59–2.13)

0.72

1.49 (0.70–3.16)

0.30

0.68 (0.40–1.17)

0.16

0.76 (0.46–1.26)

0.29

0.64 (0.40–1.02)

0.06

Tumor volume (cm³)

1.00 (1.00–1.00)

0.21

1.00 (1.00–1.00)

0.11

1.00 (1.00–1.00)

0.61

1.00 (1.00–1.00)

0.23

1.00 (1.00–1.00)

0.90

Maximum 2D tumor diameter axial (cm)

1.10 (1.00–1.20)

0.02^c

1.10 (0.90–1.20)

0.08

1.10 (0.90–1.20)

0.09

1.10 (0.90–1.20)

0.05

1.10 (0.90–1.10)

0.14

Maximum 2D tumor diameter coronal (cm)

1.10 (1.00–1.20)

0.01^c

1.10 (1.00–1.20)

0.008^c

1.10 (1.00–1.20)

0.03

1.10 (1.00–1.10)

0.02^c

1.10 (0.90–1.10)

0.11

Maximum 2D tumor diameter sagittal (cm)

1.10 (1.00–1.20)

0.01^c

1.10 (1.00–1.20)

0.01^c

1.10 (0.90–1.10)

0.14

1.10 (0.90–1.10)

0.10

1.00 (0.90–1.10)

0.38

Maximum 3D tumor diameter (cm)

1.10 (1.00–1.20)

0.003^c

1.10 (1.00–1.20)

0.007^c

1.10 (1.00–1.20)

0.02

1.10 (1.00–1.10)

0.008^c

1.10 (1.00–1.20)

0.03