Table 2 Univariate analysis of poor prognostic factors for OS in patients with pancreatic cancer

Sex

  Male

Reference

  Female

1.116

0.750–1.660

0.589

Age (years)

  ≤ 63

Reference

  > 63

1.602

1.054–2.433

0.027

Tumor location

  Head

Reference

  Body/Tail

0.761

0.488–1.185

0.227

Lymphovascular invasion

  No

Reference

  Yes

2.011

1.319–3.064

0.001

Nerve invasion

  No

Reference

  Yes

1.513

0.872–2.625

0.141

Grade

  Well/moderate

Reference

  Poor/undifferentiated

2.246

1.480–3.410

< 0.001

Tumor size (cm)

  ≤ 3

Reference

  > 3

0.988

0.664–1.471

0.953

T stage

  T1/T2

Reference

  T3/T4

1.455

0.950–2.230

0.085

N stage

  N0

Reference

  N1

1.522

1.001–2.314

0.049

  N2

4.016

2.040–7.904

< 0.001

TNM stage

  I

Reference

  II

1.571

0.986–2.502

0.047

  III

3.388

1.896–6.055

< 0.001

CA 19 − 9 (U/ml)

  ≤ 91.2

Reference

  91.2-258.1

1.365

0.795–2.343

0.259

  > 258.1

1.938

1.214–3.094

0.006

Adjuvant chemotherapy

  No

Reference

  Yes

0.602

0.405–0.895

0.012

Chemotherapy completion rate

  Complete

Reference

  Incomplete

0.751

0.476–1.187

0.221

  None

0.489

0.292–0.820

0.007

Postoperative complications

  No

Reference

  Yes

0.879

0.582–1.329

0.542

PIIN score

  ≤ 37.2

Reference

  > 37.2

2.371

1.344–4.183

0.003