Table 2.
Univariate Cox regression model in the training, internal validation, and external validation cohorts of OS.
| 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 | 1.633 | (1.531, 1.743) | <0.0001 | 1.525 | (1.409, 1.649) | <0.0001 | 1.733 | (1.340, 2.241) | <0.0001 | |
| Sex | Male | 1 | 1 | 1 | ||||||
| Female | 1.013 | (0.951, 1.079) | 0.689 | 1.15 | (1.065, 1.242) | 0.0004 | 1.15 | (0.928, 1.526) | 0.1698 | |
| Tumor location | Colon | 1 | 1 | 1 | ||||||
| Rectum | 0.684 | (0.628, 0.746) | <0.0001 | 0.606 | (0.544, 0.675) | <0.0001 | 0.428 | (0.299, 0.612) | <0.0001 | |
| Differentiation | Well | 1 | 1 | 1 | ||||||
| Moderately | 0.952 | (0.809, 1.119) | 0.5477 | 0.944 | (0.742, 1.202) | 0.6419 | 1.644 | (0.771, 3.504) | 0.1979 | |
| Poorly | 1.703 | (1.438, 2.017) | <0.0001 | 1.535 | (1.198, 1.967) | 0.0007 | 3.46 | (1.579, 7.580) | 0.0019 | |
| Undifferentiated; anaplastic | 2.078 | (1.700, 2.541) | <0.0001 | 1.925 | (1.452, 2.551) | <0.0001 | 9.651 | (3.437, 27.098) | <0.0001 | |
| Unknown | 0.676 | (0.515, 0.887) | 0.0048 | 0.854 | (0.606, 1.204) | 0.3685 | 1.897 | (0.664, 5.418) | 0.2316 | |
| Histological type | Adenocarcinoma, NOS | 1 | 1 | 1 | ||||||
| Mucinous adenocarcinoma | 1.277 | (1.135, 1.437) | <0.0001 | 1.463 | (1.275, 1.679) | <0.0001 | 1,581 | (1.049, 2.381) | 0.0285 | |
| Signet ring cell carcinoma | 2.913 | (1.948, 4.356) | <0.0001 | 1.555 | (0.965, 2.507) | 0.0698 | 4.666 | (1.475, 14.756) | 0.0087 | |
| Other | 1.177 | (1.043, 1.329) | 0.0084 | 1.29 | (1.118, 1.489) | 0.0005 | 1.352 | (0.853, 2.142) | 0.199 | |
| Size, mm | <55 | 1 | 1 | 1 | ||||||
| ≥55 | 1.319 | (1.239, 1.405) | <0.0001 | 1.217 | (1.127, 1.315) | <0.0001 | 1.529 | (1.189, 1.966) | 0.0009 | |
| TNM stage | IVA | 1 | 1 | 1 | ||||||
| IVB | 1.759 | (1.647, 1.878) | <0.0001 | 1.787 | (1.648, 1.938) | <0.0001 | 1.66 | (1.273, 2.164) | 0.0002 | |
| IVNOS | 1.523 | (1.243, 1.866) | <0.0001 | 1.299 | (1.012, 1.668) | 0.0401 | 1.975 | (1.006, 3.878) | 0.048 | |
| T stage | T1 | 1 | 1 | 1 | ||||||
| T2 | 1.24 | (0.736, 2.087) | 0.4187 | 1.507 | (0.863, 2.633) | 0.1493 | 0.804 | (0.162, 3.982) | 0.7889 | |
| T3 | 1.906 | (1.182, 3.071) | 0.0081 | 2.208 | (1.349, 3.614) | 0.0016 | 1.92 | (0.611, 6.031) | 0.2639 | |
| T4 | 3.052 | (1.892, 4.923) | <0.0001 | 3.364 | (2.054, 5.510) | <0.0001 | 3.57 | (1.131, 11.272) | 0.03 | |
| N stage | N0 | 1 | 1 | 1 | ||||||
| N1 | 1.339 | (1.207, 1.486) | <0.0001 | 1.447 | (1.274, 1.643) | <0.0001 | 1.187 | (0.833, 1.692) | 0.3419 | |
| N2 | 1.987 | (1.799, 2.195) | <0.0001 | 2.051 | (1.815, 2.317) | <0.0001 | 2.1 | (1.507, 2.926) | <0.0001 | |
| M stage | M1a | 1 | 1 | 1 | ||||||
| M1b | 1.759 | (1.647, 1.878) | <0.0001 | 1.787 | (1.648, 1.938) | <0.0001 | 1.7 | (1.309, 2.208) | <0.0001 | |
| M1NOS | 1.523 | (1.243, 1.866) | <0.0001 | 1.299 | (1.012, 1.668) | 0.0401 | 1.454 | (0.595, 3.551) | 0.4112 | |
| Radiotherapy | Yes | 1 | 1 | 1 | ||||||
| None/unknown | 1.756 | (1.542, 1.999) | <0.0001 | 2.072 | (1.764, 2.434) | <0.0001 | 1.846 | (1.167, 2.919) | 0.0088 | |
| Chemotherapy | Yes | 1 | 1 | 1 | ||||||
| None/unknown | 3.198 | (2.990, 3.421) | <0.0001 | 3.438 | (3.169, 3.730) | <0.0001 | 2.841 | (2.169, 3.721) | <0.0001 | |
| No. of sampled LNs | 0.987 | (0.983, 0.990) | <0.0001 | 0.986 | (0.981, 0.990) | <0.0001 | 0.979 | (0.963, 0.997) | 0.0188 | |
| No. of positive LNs | 1.050 | (1.045, 1.055) | <0.0001 | 1.049 | (1.042, 1.055) | <0.0001 | 1.032 | (1.012, 1.052) | 0.0012 | |
| Primary surgery | Yes | 1 | 1 | 1 | ||||||
| No | 1.672 | (0.627, 4.457) | 0.3044 | 1.199 | (0.450, 3.198) | 0.7166 | 3.311 | (0.819, 13.383) | 0.0929 | |
| Metastatic surgery | Yes | 1 | 1 | 1 | ||||||
| No | 1.596 | (1.483, 1.717) | <0.0001 | 1.692 | (1.546, 1.853) | <0.0001 | 1.978 | (1.385, 2.825) | 0.0002 | |