Table 2. Demographic and tumor characteristics of the study populations.
| LNR | Total | P (LNR B vs. LNR C) | P total | |||
|---|---|---|---|---|---|---|
| A | B | C | ||||
| Patients | 767 | 239 | 240 | 1,246 | ||
| Age | 64 [55–72] | 66 [58–73] | 64 [54–72] | 63 [50–72] | 0.069 | 0.005 |
| RNE | 22 [16–30] | 15 [10–22] | 11 [6–17] | 9 [4–16] | 0.000 | 0.000 |
| RNP | 0 | 1 [1–2] | 4 [2–6] | 0 [0–1] | 0.000 | 0.000 |
| LNR (%) | 0 | 10.5 [6.3–14.8] | 42.5 [28.6–60] | 0 [0–14.3%] | 0.000 | 0.000 |
| Survival months | 37 [14–79] | 21 [11–37] | 13 [6–22] | 25 [10–61] | 0.000 | 0.000 |
| Year interval | 0.101 | 0.009 | ||||
| 1988–2000 | 237 | 82 | 104 | 423 | ||
| 2001–2007 | 262 | 79 | 74 | 415 | ||
| 2008–2014 | 268 | 78 | 62 | 408 | ||
| Race | 0.944 | 0.137 | ||||
| White | 606 | 199 | 202 | 1007 | ||
| Black | 68 | 22 | 20 | 110 | ||
| Other | 93 | 18 | 18 | 129 | ||
| Age group | 0.061 | 0.069 | ||||
| ≤65 | 424 | 133 | 113 | 670 | ||
| >65 | 343 | 106 | 127 | 576 | ||
| Sex | 0.218 | 0.028 | ||||
| Male | 341 | 116 | 130 | 587 | ||
| Female | 426 | 123 | 110 | 659 | ||
| Marital status | 0.87 | 0.483 | ||||
| Married | 455 | 149 | 152 | 756 | ||
| Other | 277 | 81 | 80 | 438 | ||
| NA | 35 | 9 | 8 | 52 | ||
| Histologic type | 0.371 | 0.000 | ||||
| IPMN | 530 | 211 | 209 | 950 | ||
| MCN/SCN | 136 | 23 | 29 | 188 | ||
| SPN | 101 | 5 | 2 | 108 | ||
| Tumor site | 0.027 | 0.000 | ||||
| Pancreatic head | 389 | 150 | 171 | 710 | ||
| Pancreatic body & tail | 245 | 51 | 44 | 340 | ||
| Other | 28 | 5 | 7 | 40 | ||
| Overlapping | 52 | 21 | 7 | 80 | ||
| NA | 53 | 12 | 11 | 76 | ||
| Surgery type | 0.362 | 0.553 | ||||
| TP | 101 | 38 | 32 | 171 | ||
| PP | 666 | 201 | 208 | 1,075 | ||
| T stage | 0.666 | 0.000 | ||||
| T1 | 186 | 28 | 25 | 239 | ||
| T2 | 204 | 87 | 99 | 390 | ||
| T3 | 353 | 113 | 103 | 569 | ||
| T4 | 24 | 11 | 13 | 48 | ||
| RNE4 | 0.000 | 0.000 | ||||
| 1–5 | 235 | 10 | 65 | 310 | ||
| 6–10 | 179 | 58 | 66 | 303 | ||
| 11–16 | 178 | 62 | 58 | 298 | ||
| ≥17 | 175 | 109 | 51 | 335 | ||
| RNP2 | 0.000 | 0.000 | ||||
| 0 | 767 | 0 | 0 | 767 | ||
| 1 | 0 | 163 | 77 | 240 | ||
| 2 | 0 | 76 | 163 | 239 | ||
| N stage | 0.000 | 0.000 | ||||
| 767 | 0 | 0 | 767 | |||
| N1 | 0 | 220 | 112 | 332 | ||
| N2 | 0 | 19 | 128 | 147 | ||
| Metastasis | 0.136 | 0.032 | ||||
| M0 | 542 | 173 | 138 | 853 | ||
| M1 | 27 | 11 | 16 | 54 | ||
| NA | 198 | 55 | 86 | 339 | ||
| Grade | 0.368 | 0.000 | ||||
| Grade I | 188 | 39 | 31 | 258 | ||
| Grade II | 220 | 97 | 101 | 418 | ||
| Grade III, IV | 81 | 64 | 77 | 222 | ||
LNR, lymph node ratio; RNP, the number of positive regional lymph nodes; RNE, regional nodes examined; LNR A, 0; LNR B, ≤0.2; LNR C, >0.2.