Table 3 Univariate analysis

Age at surgery

 <65 years

1

 >65 years

1.573

0.907–2.729

0.107

Gender

 Female

1

 Male

1.125

0.563–2.247

0.739

Primary tumor

 T1–3

1

 T4

6.289

3.425–11.49

<0.001

 N0

1

 N1

5.812

2.088–16.39

<0.001

 Negative

1

 Positive

5.917

1.812–19.23

0.003

Venous invasion

 Negative

1

 Positive

3.135

1.541–6.369

0.002

 Negative

1

 Positive

2.387

1.115–5.102

0.025