Table 1.
Baseline characteristics N= 1,477
| Variables | N (%) | Training Set | Test Set | p-value |
|---|---|---|---|---|
| All patients | 1,477 (100%) | 754 (51.1%) | 723 (48.9%) | - |
|
| ||||
| Age | 0.98 | |||
| < 65 years | 1,039 (70.4%) | 528 (70.4%) | 508 (70.5%) | |
| ≥ 65 years | 438 (29.6%) | 226 (29.6%) | 215 (29.5) | |
|
| ||||
| Gender | 0.54 | |||
| Male | 723 (48.9%) | 375 (49.7%) | 348 (48.1%) | |
| Female | 754 (51.1%) | 379 (50.3%) | 375 (51.9%) | |
|
| ||||
| ASA Class | 0.89 | |||
| 1 | 65 (4.7%) | 35 (4.9%) | 30 (4.6%) | |
| 2 | 568 (41.3%) | 296 (41.2%) | 272 (41.5%) | |
| 3 | 714 (52.0%) | 372 (51.7%) | 342 (52.2%) | |
| 4 | 27 (2.0%) | 16 (2.2%) | 11 (1.7%) | |
| NA | 103 | 35 | 68 | |
|
| ||||
| Functional Status | 0.33 | |||
| Non-functional | 576 (39.6%) | 305 (40.8%) | 271 (38.3%) | |
| Functional | 880 (60.4%) | 443 (59.2%) | 437 (61.7%) | |
| NA* | 21 | 6 | 15 | |
|
| ||||
| Genetic Syndrome | 0.91 | |||
| Not Syndromic | 1,358 (91.9%) | 695 (93.6%) | 663 (94.1%) | |
| MEN 1 | 72 (5.0%) | 38 (5.1%) | 34 (4.8%) | |
| VHL | 11 (0.7%) | 7 (0.9%) | 4 (0.6%) | |
| Neurofibromatosis | 5 (0.3%) | 2 (0.3%) | 3 (0.4%) | |
| Tuberous Sclerosis | 2 (0.1%) | 1 (0.1%) | 1 (0.1%) | |
| NA* | 29 | 11 | 18 | |
|
| ||||
| Multifocal | 0.95 | |||
| No | 1,222 (93.6%) | 615 (93.6%) | 607 (93.5%) | |
| Yes | 84 (6.4%) | 42 (6.4%) | 42 (6.5%) | |
| NA* | 171 | 97 | 74 | |
|
| ||||
| Primary | 0.75 | |||
| Ampulla | 28 (1.9%) | 16 (2.1%) | 12 (1.7%) | |
| Appendix | 48 (3.3%) | 19 (2.5%) | 29 (4.0%) | |
| Colon | 34 (2.3%) | 14 (1.9%) | 20 (2.8%) | |
| Duodenum | 101 (6.8%) | 53 (7.0%) | 48 (6.6%) | |
| Gallbladder | 4 (0.3%) | 1 (0.1%) | 3 (0.4%) | |
| Liver | 12 (0.8%) | 8 (1.1%) | 4 (0.6%) | |
| Pancreas | 948 (64.2%) | 489 (64.9%) | 459 (63.5%) | |
| Rectum | 37 (2.5%) | 23 (3.1%) | 14 (1.9%) | |
| Small Bowel | 198 (13.4%) | 101 (13.4%) | 97 (13.4%) | |
| Stomach | 67 (4.5%) | 29 (3.9%) | 38 (5.1%) | |
|
| ||||
| Tumor Differentiation | 0.79 | |||
| Well differentiated | 1,101 (88.3%) | 562 (88.2%) | 539 (88.4%) | |
| Moderately differentiated | 118 (9.5%) | 59 (9.3%) | 59 (9.7%) | |
| Poorly differentiated | 28 (2.2%) | 16 (2.5%) | 12 (1.9%) | |
| NA* | 230 | 117 | 113 | |
|
| ||||
| Ki-67 Index, median (IQR) | 2.0% (1–5) | 2.6% (1–5) | 2.0% (1–5) | 0.87 |
|
| ||||
| Lymphnodes Status | 0.79 | |||
| Negative | 704 (60.7%) | 368 (61.7%) | 336 (59.6%) | |
| 1–3 Positives | 317 (27.3%) | 156 (26.2%) | 161 (28.5%) | |
| >3 Positives | 139 (12.0%) | 72 (12.0%) | 67 (11.9%) | |
| NA* | 317 | 158 | 159 | |
|
| ||||
| Tumor Size | 0.55 | |||
| < 3 cm | 1,031 (69.8%) | 521 (69.1%) | 510 (70.5%) | |
| ≥ 3 cm | 446 (30.2%) | 233 (30.9%) | 213 (29.5%) | |
|
| ||||
| Final Margin Status | 0.23 | |||
| Negative | 1,246 (84.9%) | 644 (85.9%) | 602 (83.7%) | |
| Positive | 222 (15.1%) | 105 (14.1%) | 117 (16.3%) | |
| NA* | 9 | 5 | 4 | |
|
| ||||
| Perivascular Invasion | 0.09 | |||
| Absent | 683 (63.8%) | 369 (66.3%) | 314 (61.2%) | |
| Present | 387 (36.2%) | 188 (33.7%) | 199 (38.8%) | |
| NA* | 407 | 197 | 210 | |
|
| ||||
| Perineural Invasion | 0.90 | |||
| Absent | 706 (74.7%) | 366 (74.5%) | 340 (74.9%) | |
| Present | 239 (25.3%) | 125 (25.5%) | 114 (25.1%) | |
| NA* | 532 | 263 | 269 | |
NA=not available;
*
multiple imputation was used to address missing data