Table 2 Identifications of factors associated with CSS and OS in SCLC patients with liver metastasis

Age, n (%), years

 ≤ 65

1

1

 > 65

1.303 (1.238–1.372)

< 0.001

1.325 (1.261–1.393)

< 0.001

Gender, n (%)

 Female

1

1

 Male

1.113 (1.057–1.171)

< 0.001

1.135 (1.080–1.192)

< 0.001

Race, n (%)

 Black

1

1

 White

1.068 (0.970–1.177)

0.178

1.050 (0.956–1.153)

0.305

 Others

0.971 (0.822–1.147)

0.733

0.973 (0.829–1.143)

0.741

Marital status, n (%)

 Others

1

1

 Married

0.907 (0.863–0.955)

< 0.001

0.896 (0.853–0.942)

< 0.001

Primary sites, n (%)

 Multiple sites

1

1

 Upper lobe

0.932 (0.756–1.148)

0.508

0.935 (0.762–1.147)

0.518

 Middle lobe

0.877 (0.683–1.126)

0.304

0.894 (0.701–1.141)

0.369

 Lower lobe

0.916 (0.740–1.134)

0.420

0.931 (0.756–1.146)

0.500

 Main bronchus

0.894 (0.718–1.113)

0.315

0.890 (0.718–1.103)

0.286

 NOS

1.087 (0.879–1.345)

0.441

1.101 (0.894–1.356)

0.366

Tumor size, n (%)

 0–24 mm

1

1

 25–37 mm

1.025 (0.954–1.102)

0.498

1.030 (0.960–1.106)

0.404

 38–59 mm

1.018 (0.947–1.094)

0.634

1.021 (0.951–1.095)

0.572

 ≥ 60 mm

0.944 (0.878–1.015)

0.120

0.948 (0.883–1.017)

0.135

T, n (%)

 T0

1

1

 T1

0.925 (0.718–1.191)

0.544

0.906 (0.710–1.155)

0.424

 T2

1.018 (0.800–1.295)

0.885

0.981 (0.779–1.236)

0.873

 T3

1.068 (0.839–1.360)

0.594

1.034 (0.820–1.305)

0.775

 T4

1.004 (0.791–1.274)

0.976

0.972 (0.773–1.223)

0.811

 Tx

1.169 (0.918–1.489)

0.206

1.136 (0.900–1.433)

0.284

N, n (%)

 N0

1

1

 N1

0.959 (0.841–1.093)

0.528

0.628

0.945 (0.832–1.074)

0.387

0.592

 N2

0.979 (0.899–1.066)

0.628

0.628

0.978 (0.900–1.062)

0.592

0.592

 N3

0.923 (0.839–1.015)

0.097

0.291

0.926 (0.844–1.017)

0.107

0.321

 Nx

1.264 (1.115–1.433)

< 0.001

< 0.001

1.267 (1.121–1.431)

< 0.001

< 0.001

Metastatic sites, n (%)

 Bone

1

1

 Brain

1.116 (1.000–1.247)

0.051

0.051

1.110 (0.996–1.237)

0.059

0.059

 Lung

1.189 (1.075–1.316)

0.001

0.004

1.206 (1.092–1.331)

< 0.001

< 0.001

 Multiple metastases

1.115 (1.031–1.206)

0.007

0.021

1.118 (1.036–1.207)

0.004

0.012

 No metastases/unknown

1.068 (1.002–1.139)

0.042

0.051

0

1.087 (1.021–1.157)

0.009

0.018

Surgery of primary site, n (%)

 Not/unknown

1

1

 Yes

0.652 (0.440–0.966)

0.033

0.619 (0.418–0.916)

0.017

Surgery of metastatic site, n (%)

 Not/unknown

1

1

 Yes

0.927 (0.776–1.109)

0.407

0.938 (0.789–1.116)

0.471

Chemotherapy, n (%)

 Not/unknown

1

1

 Yes

0.232 (0.219–0.246)

< 0.001

0.225 (0.213–0.238)

< 0.001

Radiotherapy, n (%)

 Not/unknown

1

1

 Yes

0.627 (0.593–0.664)

< 0.001

0.616 (0.583–0.651)

< 0.001