Table 2. Baseline characteristics of the discovery and the validation cohorts.
| Variable | Discovery cohort n (%) | Validation cohort n (%) | p-value |
| Sex | |||
| Male | 327 (61.50%) | 133 (52.78%) | |
| Female | 205 (38.50%) | 119 (47.22%) | p = 0.021 |
| Median age in years (range) | 61.4 (20.7–75) | 68.7 (25.3–91.6) | p<0.001 |
| Histology | |||
| non-mucinous | 471 (88.50%) | 211 (83.73%) | |
| Mucinous | 61 (11.50%) | 41 (16.27%) | p = 0.062 |
| Location | |||
| Colon | 353 (66.40%) | 202 (80.16%) | |
| Rectum | 179 (33.60%) | 50 (19.84%) | p<0.001 |
| Stage | |||
| I | 99 (18.60%) | 48 (19.05%) | |
| II | 206 (38.70%) | 88 (34.92%) | |
| III | 175 (32.90%) | 68 (26.98%) | |
| IV | 52 (9.80%) | 41 (16.27%) | |
| Unknown | – | 7 (2.78%) | p = 0.034 |
| Grade | |||
| well diff./moderately diff. | 489 (91.90%) | 211 (83.73%) | |
| poorly diff./undiff. | 39 (7.30%) | 37 (14.68%) | |
| Unknown | 4 (0.80%) | 4 (1.59%) | p = 0.001 |
| * Invasion | |||
| Absence | 326 (61.30%) | 64 (25.40%) | |
| Presence | 166 (31.20%) | 101 (40.08%) | |
| Unknown | 40 (7.50%) | 87 (34.52%) | p<0.001 |
| OS status | |||
| Dead | 177 (33.30%) | 155 (61.51%) | |
| Alive | 354 (66.60%) | 97 (38.49%) | |
| Unknown | 1 (0.10%) | – | p<0.001 |
| Median OS follow-up time in years (range) | 6.4 (0.4–10.9) | 5.4 (0–12.48) | |
| DFS status | |||
| Event | 208 (39.10%) | 167 (66.27%) | |
| no event | 323 (60.71%) | 85 (33.73%) | |
| Unknown | 1 (0.19%) | – | p<0.001 |
| Median DFS follow-up time in years (range) | 6 (0.2–10.9) | 3.3 (0–12.5) | |
| MSI Status | |||
| MSI-H | 56 (10.50%) | 24 (9.52%) | |
| MSI-L/MSS | 455 (85.50%) | 228 (90.48%) | |
| Unknown | 21 (4%) | p = 0.543 | |
| Familial risk | |||
| Low | 256 (48.10%) | Na | nd |
| Intermediate/high | 276 (59.10%) | ||
| BRAF1 Val600Glu mutation | |||
| Presence | 49 (9.20%) | Na | nd |
| Absence | 435 (81.80%) | ||
| Unknown | 48 (9%) | ||
| 5-FU based treatment | |||
| 5-FU treated | 330 (62.03%) | 88 (34.92%) | |
| other/no chemotherapy | 199 (37.41%) | 148 (58.73%) | |
| Unknown | 3 (0.56%) | 16 (6.35%) | p<0.001 |
*
Vascular invasion and lymphatic invasion were highly correlated in the discovery cohort (p<0.001). Since data for vascular invasion in the validation cohort was not available, vascular invasion in the discovery cohort and lymphatic invasion in the validation cohort were compared with each other. diff: differentiated, n: number of patients, na: not available, nd: not done.