Table 3 Univariate and multivariate analysis of overall survival in type IVa and IVb patients

Age at diagnosis (Child/Adult)

10.494

0.001

1.440 (0.203–10.229)

0.715

0.851

0.356

Sex (Female/Male)

0.075

0.785

5.691

0.017

1.279 (0.929–1.762)

0.132

Diagnosis year

4.734

0.094

11.611

0.003

1

  < 1998/1998–2004

1.350 (0.932–1.956)

0.112

  < 1998/≥2004

2.544 (1.669–3.876)

< 0.001

Race

1.228

0.541

10.651

0.005

1

 Others/White

1.214 (0.710–2.076)

0.479

 Others/Black

2.365 (1.214–4.606)

0.011

Clinical node stage (cN0/cN+)

0.518

0.471

296.560 (3.493–25,180.669)

0.012

34.543

< 0.001

1.403 (0.654–3.011)

0.384

SEER stage

9.727

0.008

1

43.991

< 0.001

1

 Localized/Regional

0.483 (0.044–5.314)

0.552

1.674 (1.090–2.572)

0.019

 Localized/Distant

0.016 (0.000–1.982)

0.093

2.282 (0.961–5.421)

0.062

Radiation therapy (No/Yes)

24.005

< 0.001

79.660 (1.931–3285.577)

0.021

1.012

0.292

Chemotherapy (No/Yes)

0.134

0.714

27.402

< 0.001

1.669 (1.187–2.348)

0.003

Lymph node dissection (No/Yes)

6.642

0.010

1.090 (0.422–2.818)

0.013

9.604

0.002

1.420 (0.849–2.376)

0.182