Table 1.
Baseline characteristics
| Low-risk | High-risk | |||||||
|---|---|---|---|---|---|---|---|---|
| All patients | No SYS | SYS | P-value | All patients | No SYS | SYS | P-value | |
| Sample size | 1288 | 426 (33.1%) | 862 (66.9%) | - | 732 | 158 (21.7%) | 574 (78.4%) | - |
| Age (median, IQR) | 65.5 (57.0-72.3) | 67.0 (60.0-74.0) | 64.4 (55.7-71.4) | <0.001 | 62.1 (53.0-70.0) | 64.0 (58.0-72.0) | 62.0 (51.6-69.4) | 0.15 |
| Gender | 0.63 | 0.71 | ||||||
| Male | 794 (61.6%) | 267 (62.7%) | 527 (61.1%) | 448 (61.2%) | 99 (62.7%) | 349 (60.8%) | ||
| Female | 494 (38.4%) | 159 (37.3%) | 335 (38.9%) | 284 (38.8%) | 59 (37.3%) | 225 (39.2%) | ||
| Primary tumor location | 0.01 | 0.60 | ||||||
| Right-sided | 288 (23.0%) | 79 (19.2%) | 209 (24.9%) | 196 (27.3%) | 41 (26.5% | 155 (27.5%) | ||
| Left-sided | 559 (44.7%) | 180 (43.7%) | 379 (45.2%) | 327 (45.5%) | 67 (43.2%) | 260 (46.2%) | ||
| Rectum | 404 (32.3%) | 153 (37.1%) | 251 (29.9%) | 195 (27.2%) | 47 (30.3%) | 148 (26.3%) | ||
| Missing | 37 | 14 | ||||||
| Nodal status primary tumor | 0.09 | 0.84 | ||||||
| N0 | 751 (58.6%) | 262 (61.9%) | 489 (57.0%) | 77 (10.6%) | 16 (10.1%) | 61 (10.7%) | ||
| N+ | 530 (41.4%) | 161 (38.1%) | 369 (43.0%) | 652 (89.4%) | 142 (89.9%) | 510 (89.3%) | ||
| Missing | 7 | 3 | ||||||
| Disease free interval | 0.002 | 0.82 | ||||||
| ≤ 12 months | 609 (47.3%) | 175 (41.1%) | 434 (50.3%) | 684 (93.4%) | 147 (93.0%) | 147 (93.0%) | ||
| > 12 months | 679 (52.7%) | 251 (58.9%) | 428 (49.7%) | 48 (6.6%) | 11 (7.0%) | 11 (7.0%) | ||
| Number CRLM | 0.01 | 0.59 | ||||||
| ≤ 1 | 882 (68.5%) | 311 (73.0%) | 571 (66.2%) | 80 (11.0%) | 19 (12.2%) | 61 (10.6%) | ||
| > 1 | 406 (31.5%) | 115 (27.0%) | 291 (33.8%) | 649 (89.0%) | 137 (87.8%) | 512 (89.4%) | ||
| Missing | 3 | |||||||
| Size largest tumor | 0.02 | 0.33 | ||||||
| ≤ 5cm | 1079 (84.6%) | 337 (81.2%) | 742 (86.2%) | 462 (63.7%) | 104 (67.1%) | 358 (62.8%) | ||
| > 5cm | 197 (15.4%) | 78 (18.8%) | 119 (13.8%) | 263 (36.3%) | 51 (32.9%) | 212 (37.2%) | ||
| Missing | 12 | 7 | ||||||
| CEA | 0.27 | 0.78 | ||||||
| ≤ 200 μg/L | 1204 (97.3%) | 400 (96.6%) | 804 (97.7%) | 531 (78.9%) | 118 (79.7%) | 413 (78.7%) | ||
| > 200 μg/L | 33 (2.7%) | 14 (3.4%) | 19 (2.3%) | 142 (21.1%) | 30 (20.3%) | 112 (21.3%) | ||
| Missing | 51 | 59 | ||||||
| Resection margin involved | 0.66 | 0.65 | ||||||
| Yes | 109 (8.5%) | 38 (9.0%) | 71 (8.3%) | 115 (15.7%) | 23 (14.6%) | 92 (16.1%) | ||
| No | 1166 (91.5%) | 382 (91.0%) | 784 (91.7%) | 616 (83.3%) | 135 (85.4%) | 481 (83.9%) | ||
| Missing | 13 | 1 | ||||||
| Tumor ablation at time of resection | 0.09 | 0.90 | ||||||
| Yes | 78 (6.1%) | 19 (4.5%) | 59 (6.8%) | 165 (22.5%) | 35 (22.2%) | 130 (22.6%) | ||
| No | 1210 (93.9%) | 407 (95.5%) | 803 (93.2%) | 567 (77.5%) | 123 (77.8%) | 444 (77.4%) | ||