Table 1. Patient clinicopathological characteristics.
| Characteristic | Training cohort (n=327) | Validation cohort (n=164) | |||||
|---|---|---|---|---|---|---|---|
| MSS (n=291) | MSI (n=36) | P value | MSS (n=149) | MSI (n=15) | P value | ||
| Gender, male/female | 195/96 | 27/9 | 0.33 | 88/61 | 8/7 | 0.67 | |
| Age, mean (SD), years | 60.5±4.9 | 59.2±12.8 | 0.59 | 60.7±11.3 | 55.4±12.1 | 0.09 | |
| MR-T category | 0.51 | 0.61 | |||||
| T1 | 17 | 2 | 9 | 0 | |||
| T2 | 117 | 18 | 61 | 8 | |||
| T3 | 146 | 16 | 75 | 7 | |||
| T4 | 11 | 0 | 4 | 0 | |||
| CEA, mean (SD) | 11.99±0.16 | 7.65±15.43 | 0.41 | 10.39±28.39 | 4.22±4.12 | 0.42 | |
| CA19-9, mean (SD) | 23.55±5.86 | 15.18±15.59 | 0.22 | 16.76±18.08 | 25.32±36.93 | 0.13 | |
The differences in characteristic dichotomous variables between the two cohorts were calculated using the Chi-square test or Fisher’s exact test, whereas the Mann-Whitney U test was conducted to compare differences in actual variables. MSS, microsatellite stability; MSI, microsatellite instability; CEA, carcinoembryonic antigen; CA19-9, carbohydrate antigen 19-9; SD, standard deviation.