Table 2 Cox regression analysis of overall survival and disease-specific survival of the entire cohort

Age at diagnosis (years)

1.041 (1.030–1.053)

< 0.001

1.017 (1.006–1.028)

0.002

Sex (Female/Male)

1.309 (0.961–1.783)

0.087

1.307 (0.886–1.928)

0.177

 Others

1(Reference)

1(Reference)

 White

1.441 (0.844–2.458)

0.181

1.265 (0.654–2.445)

0.485

 Black

2.879 (1.494–5.550)

0.002

2.392 (1.068–5.355)

0.034

  < 1998

1(Reference)

1(Reference)

 1998–2004

1.560 (1.080–2.255)

0.018

1.855 (1.194–2.882)

0.006

  ≥ 2004

2.630 (1.743–3.967)

< 0.001

2.742 (1.632–4.607)

< 0.001

 Localized

1(Reference)

1(Reference)

 Regional

1.613 (1.056–2.465)

0.027

2.696 (1.427–5.095)

0.002

 Advanced

2.051 (0.909–4.626)

0.084

4.043 (1.374–11.900)

0.011

Clinical node status (cN0/cN+)

1.637 (0.801–3.345)

0.177

1.480 (0.606–3.616)

0.390

Histology (IVa/IVb)

1.697 (0.827–3.482)

0.149

2.836 (1.108–7.260)

0.030

Chemotherapy (No/Yes)

2.041 (1.465–2.845)

< 0.001

2.147 (1.433–3.219)

< 0.001

Radiation (No/Yes)

0.869 (0.643–1.175)

0.362

1.134 (0.760–1.692)

0.538

Lymph node detection (No/Yes)

1.250 (0.756–2.066)

0.384

1.231 (0.679–2.231)

0.494