Table 3.
Univariate Cox regression model in the training, internal validation, and external validation cohorts of CSS.
| Variables | Training cohort | Internal validation cohort | External validation cohort | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| HR | 95% CI | P | HR | 95% CI | P | HR | 95% CI | P | ||
| Age | <60 | 1 | 1 | 1 | ||||||
| ≥60 | 1.595 | (1.480, 1.719) | <0.0001 | 1.539 | (1.405, 1.686) | <0.0001 | 1.844 | (1.384, 2.458) | <0.0001 | |
| Sex | Male | 1 | 1 | 1 | ||||||
| Female | 0.991 | (0.921, 1.066) | 0.8009 | 1.181 | (1.080, 1.291) | 0.0003 | 1.235 | (0.938, 1.627) | 0.133 | |
| Tumor location | Colon | 1 | 1 | 1 | ||||||
| Rectum | 0.676 | (0.611, 0.747) | <0.0001 | 0.591 | (0.521, 0.670) | <0.0001 | 0.417 | (0.279, 0.621) | <0.0001 | |
| Differentiation | Well | 1 | 1 | 1 | ||||||
| Moderately | 1.051 | (0.864, 1.278) | 0.6212 | 0.892 | (0.679, 1.172) | 0.4121 | 1.893 | (0.775, 4.623) | 0.1612 | |
| Poorly | 1.837 | (1.497, 2.253) | <0.0001 | 1.44 | (1.087, 1.908) | 0.011 | 3.789 | (1.505, 9.544) | 0.0047 | |
| Undifferentiated; anaplastic | 2.335 | (1.838, 2.967) | <0.0001 | 1.74 | (1.259, 2.406) | 0.0008 | 13.806 | (4.421, 43.118) | <0.0001 | |
| Unknown | 0.777 | (0.567, 1.064) | 0.1161 | 0.808 | (0.545, 1.198) | 0.2886 | 1.557 | (0.417, 5.809) | 0.5099 | |
| Histological type | Adenocarcinoma, NOS | 1 | 1 | 1 | ||||||
| Mucinous adenocarcinoma | 1.289 | (1.125, 1.477) | 0.0003 | 1.393 | (1.182, 1.641) | <0.0001 | 1.378 | (0.856, 2.217) | 0.1871 | |
| Signet ring cell carcinoma | 2.496 | (1.501, 4.150) | 0.0004 | 1.365 | (0.755, 2.470) | 0.3065 | 1.901 | (0.264, 13.690) | 0.5237 | |
| Other | 1.014 | (0.872, 1.178) | 0.8576 | 1.301 | (1.102, 1.535) | 0.0019 | 1.286 | (0.770, 2.149) | 0.3366 | |
| Size, mm | <55 | 1 | 1 | 1 | ||||||
| ≥55 | 1.248 | (1.160, 1.343) | <0.0001 | 1.168 | (1.068, 1.277) | 0.0007 | 1.544 | (1.169, 2.040) | 0.0022 | |
| TNM stage | IVA | 1 | 1 | 1 | ||||||
| IVB | 1.799 | (1.667, 1.941) | <0.0001 | 1.749 | (1.592, 1.923) | <0.0001 | 1.856 | (1.388, 2.480) | <0.0001 | |
| IVNOS | 1.353 | (1.052, 1.740) | 0.0185 | 1.199 | (0.888, 1.620) | 0.2367 | 2.266 | (1.104, 4.649) | 0.0257 | |
| T stage | T1 | 1 | 1 | 1 | ||||||
| T2 | 1.533 | (0.811, 2.898) | 0.1884 | 1.229 | (0.680, 2.221) | 0.494 | 0.806 | (0.163, 3.997) | 0.7918 | |
| T3 | 2.234 | (1.235, 4.042) | 0.0079 | 1.833 | (1.101, 3.051) | 0.0198 | 1.544 | (0.490, 4.865) | 0.4586 | |
| T4 | 3.487 | (1.926, 6.314) | <0.0001 | 2.573 | (1.543, 4.289) | 0.0003 | 3.075 | (0.970, 9.746) | 0.0563 | |
| N stage | N0 | 1 | 1 | 1 | ||||||
| N1 | 1.412 | (1.251, 1.593) | <0.0001 | 1.474 | (1.273, 1.708) | <0.0001 | 1.268 | (0.858, 1.874) | 0.2333 | |
| N2 | 1.994 | (1.775, 2.240) | <0.0001 | 2.056 | (1.784, 2.369) | <0.0001 | 2.049 | (1.413, 2.972) | 0.0002 | |
| M stage | M1a | 1 | 1 | 1 | ||||||
| M1b | 1.799 | (1.667, 1.941) | <0.0001 | 1.749 | (1.592, 1.923) | <0.0001 | 1.89 | (1.419, 2.518) | <0.0001 | |
| M1NOS | 1.353 | (1.052, 1.740) | 0.0185 | 1.199 | (0.888, 1.620) | 0.2367 | 1.858 | (0.757, 4.559) | 0.176 | |
| Radiotherapy | Yes | 1 | 1 | 1 | ||||||
| None/unknown | 1.843 | (1.581, 2.149) | <0.0001 | 2.008 | (1.671, 2.412) | <0.0001 | 2.046 | (1.207, 3.467) | 0.0078 | |
| Chemotherapy | Yes | 1 | 1 | 1 | ||||||
| None/unknown | 3.185 | (2.945, 3.444) | <0.0001 | 3.352 | (3.047, 3.687) | <0.0001 | 2.677 | (1.977, 3.624) | <0.0001 | |
| No. of sampled LNs | 0.985 | (0.981, 0.989) | <0.0001 | 0.986 | (0.981, 0.991) | <0.0001 | 0.977 | (0.959, 0.996) | 0.0196 | |
| No. of positive LNs | 1.047 | (1.041, 1.053) | <0.0001 | 1.049 | (1.042, 1.056) | <0.0001 | 1.027 | (1.004, 1.049) | 0.0191 | |
| Primary surgery | Yes | 1 | 1 | 1 | ||||||
| No | 2.305 | (0.866, 6134) | 0.0945 | 1.629 | (0.611, 4.347) | 0.3294 | 4.236 | (1.045, 17.171) | 0.0432 | |
| Metastatic surgery | Yes | 1 | 1 | 1 | ||||||
| No | 1.615 | (1.483, 1.758) | <0.0001 | 1.7 | (1.530, 1.888) | <0.0001 | 1.818 | (1.242, 2.663) | 0.0021 | |