Table 2 Univariate and multivariate analyses of overall survival in PDAC patients (n = 97)

Gender (Female vs. Male)

0.838

0.470–1.494

0.549

Age (≥ 60y vs. < 60y)

1.071

0.562–2.041

0.834

Location (Body + tail vs. Head)

0.635

0.344–1.171

0.146

Tumor_differentiation (G3 vs. G1 + G2)

1.015

0.578–1.781

0.96

TNM stage (III + IV vs. I + II)

1.479

0.846–2.588

0.17

T stage (T3 + T4 vs. T1 + T2)

1.882

1.086–3.262

0.024*

1.621

0.870–3.021

0.128

 N stage (N1 + N2 vs. N0)

1.022

0.593–1.761

0.939

Nerve invasion (Yes vs. No)

2.038

0.634–6.549

0.232

Major vascular invasion (Yes vs. No)

1.907

0.957–3.801

0.067

1.363

0.633–2.936

0.428

Serum CA19_9 (≥ 37U/ml vs. < 37U/ml)

1.442

0.615–3.380

0.399

CircSTX6 expression (High vs. Low)

2.025

1.162–3.528

0.013*

3.013

1.655–5.486

< 0.001***

miR-449b-5p expression (High vs. Low)

0.47

0.269–0.820

0.008**

0.426

0.232–0.780

0.006**