Table 2. Univariate and multivariate Cox regression analysis (LNR cut-off value, 0 and 0.40).
| Variable | N | Univariate | Multivariate | ||||
|---|---|---|---|---|---|---|---|
| P-value* | HR | 95%CI | P-value | HR | 95%CI | ||
| Age | |||||||
| ≤ 60 years | 732 | reference | reference | ||||
| > 60 years | 541 | < 0.001 | 2.040 | 1.567–2.655 | < 0.001 | 2.186 | 1.665–2.871 |
| Gender | |||||||
| Male | 680 | reference | reference | ||||
| Female | 593 | 0.003 | 0.663 | 0.507–0.868 | 0.003 | 0.659 | 0.502–0.864 |
| Race | |||||||
| White | 1022 | reference | |||||
| Black | 131 | 0.457 | 0.840 | 0.530–1.331 | |||
| Other | 120 | 0.334 | 0.777 | 0.466–1.296 | |||
| Site | |||||||
| Head | 417 | reference | reference | ||||
| Body | 169 | 0.008 | 0.494 | 0.294–0.828 | 0.008 | 0.492 | 0.290–0.833 |
| Tail | 469 | 0.041 | 0.729 | 0.538–0.987 | 0.031 | 0.710 | 0.519–0.970 |
| Other | 218 | 0.163 | 0.768 | 0.530–1.113 | 0.180 | 0.768 | 0.522–1.130 |
| Surgical Procedures | |||||||
| Enucleation | 20 | reference | |||||
| PP | 736 | 0.413 | 0.618 | 0.196–1.952 | |||
| TP | 136 | 0.693 | 1.268 | 0.390–4.120 | |||
| Whipple | 348 | 0.846 | 1.121 | 0.354–3.549 | |||
| Surgery NOS | 33 | 0.341 | 0.483 | 0.108–2.161 | |||
| Tumor Size | |||||||
| ≤ 2 cm | 347 | reference | |||||
| > 2 cm | 926 | 0.006 | 1.650 | 1.155–2.358 | |||
| Lymph Node Metastasis | |||||||
| Negative | 742 | reference | |||||
| Positive | 531 | < 0.001 | 1.914 | 1.467–2.497 | |||
| Number of Examined Lymph Nodes | |||||||
| ≤ 12 | reference | ||||||
| > 12 | 0.074 | 1.276 | 0.977–1.667 | ||||
| SEER Grade | |||||||
| I | 784 | reference | reference | ||||
| II | 185 | 0.491 | 1.166 | 0.754–1.802 | 0.623 | 1.118 | 0.718–1.740 |
| III | 95 | < 0.001 | 5.073 | 3.516–7.321 | < 0.001 | 3.645 | 2.501–5.310 |
| IV | 16 | < 0.001 | 4.071 | 1.886–8.789 | 0.008 | 2.876 | 1.320–6.270 |
| Unknown | 193 | 0.001 | 1.752 | 1.259–2.438 | 0.003 | 1.665 | 1.193–2.324 |
| AJCC Stage 6th | |||||||
| I | 493 | reference | |||||
| II | 513 | 0.001 | 1.906 | 1.319–2.754 | 0.128 | 1.411 | 0.906–2.197 |
| III | 24 | 0.001 | 3.457 | 1.620–7.376 | 0.008 | 2.933 | 1.325–6.490 |
| IV | 243 | < 0.001 | 3.972 | 2.736–5.766 | < 0.001 | 3.297 | 2.089–5.203 |
| Lymph Node Ratio | |||||||
| LNR = 0 | 742 | reference | reference | ||||
| 0 < LNR ≤ 0.40 | 369 | 0.001 | 1.665 | 1.233–2.249 | 0.621 | 1.095 | 0.765–1.567 |
| LNR > 0.40 | 162 | < 0.001 | 2.445 | 1.749–3.419 | 0.012 | 1.650 | 1.117–2.438 |
*Only factor with P-value ≤ 0.05 was included in multivariate analysis; variable and P-value in bold mean statistically significant in multivariate analysis. PP, Partial Pancreatectomy; TP, Total Pancreatectomy; NOS, not otherwise specified; SEER Grade [34]; AJCC, American Joint Committee on Cancer.