Table 3 Multivariable analysis of overall survival in 1435 patients according to clinicopathological variables

Age

1.011

1.002–1.019

0.014

1.010

1.002–1.019

0.015

Male (reference)

1

0.371

Female

0.896

0.706–1.139

0.908

0.715–1.155

0.342

Upper tumor (reference)

1

Middle tumor

1.150

0.660–2.005

0.622

1.169

0.671–2.038

0.581

Lower tumor

1.113

0.637–1.945

0.708

1.130

0.647–1.974

0.668

G1 (reference)

1

G2

1.503

1.153–1.959

0.003

1.516

1.163–1.976

0.002

G3

1.184

0.942–1.488

0.148

1.180

0.939–1.483

0.157

T1 (reference)

1

T2

1.708

1.182–2.649

0.004

1.666

1.153–2.406

0.006

T3

2.140

1.521–3.009

<0.001

2.081

1.483–2.919

<0.001

T4

2.781

1.855–4.171

<0.001

2.691

1.797–4.028

<0.001

N0 (reference)

1

N1

1.746

1.442–2.116

<0.001

1.716

1.416–2.078

<0.001

N2

2.974

2.422–3.652

<0.001

2.961

2.412–3.636

<0.001

N3

5.128

3.969–6.626

<0.001

5.091

3.939–6.580

<0.001

Vascular invasion

1.113

0.917–1.350

0.278

1.108

0.913–1.344

0.299

Perineural involvement

1.091

0.912–1.305

0.343

1.098

0.918–1.314

0.307

Number of resected lymph nodes

0.987

0.980–0.994

<0.001

0.987

0.980–0.994

<0.001

Tumor length

1.201

1.032–1.403

0.018

1.064

1.026–1.103

<0.001