Table 3 Univariate analysis for disease-free survival and overall survival

Age(years)

0.944

0.84

  ≥ 60 (vs. < 60)

0.985

0.632–1.537

0.954

0.594–1.534

Gender

0.456

0.416

 Female (vs. Male)

1.176

0.754–1.835

1.21

0.754–1.943

Tumor sites

0.69

0.629

 Body/tail (vs. Head)

0.918

0.589–1.431

0.893

0.555–1.439

Tumor size

0.181

0.052

 T3-4 (vs. T1-2)

1.379

0.836–2.274

1.658

0.967–2.843

TNM stage

0.003

0.001

 III-IV (vs. I-II)

2.399

1.284–4.482

2.849

1.428–5.683

Tumor differentiation

0.009

0.002

 Poor (vs. Well/moderate)

1.784

1.118–2.846

2.059

1.269–3.34

Resection margins

0.282

0.089

 Positive (vs. Negative)

1.338

0.77–2.326

1.601

0.912–2.81

Lymph node metastasis

0.314

0.06

 Yes (vs. No)

1.238

0.797–1.923

1.535

0.961–2.453

AREG expression

0.021

0.003

 Positive (vs. Negative)

1.688

1.059–2.691

2.043

1.238–3.374

EGFRvIII expression

0.466

0.466

 Positive (vs. Negative)

1.256

0.663–2.381

1.292

0.637–2.623

AREG/EGFR coexpression

0.08

0.166

 Negative (vs. Positive)

0.853

0.646–1.128

0.831

0.619–1.115