Table 1 Univariate and multivariate analysis for overall survival (OS)

Gender

0.8049

0.5326–1.216

0.2889

Hypoxia score

1.834

1.216–2.767

0.0062*

1.654

1.028–2.662

0.038*

Grade

–

–

0.149

G1

Reference

G2

2.004

1.160–3.463

0.0283*

G3/G4

2.401

1.309–4.405

0.0089*

Stage

–

–

0.142

I

Reference

II

2.271

1.293–3.989

0.0292*

III/IV

1.029

0.2640–4.010

0.9665

Location (head vs body and tail)

0.5812

0.3501–0.9649

0.0732

Residual tumor

1.632

1.020–2.609

0.0247*

1.568

1.005–2.447

0.048*