Table 1. Patient and tumor characteristics.
| Characteristics | n (%) | P | |
| Training cohort (N=552) | Validation cohort (N=252) | ||
| NCRT, neoadjuvant chemoradiotherapy; MRI, magnetic resonance imaging; EMVI, extramural venous invasion; CEA, carcinoma embryonic antigen; DTA, distance from inferior part of tumor to anal verge; DMRF, distance between the deepest tumor invasion and mesorectal fascia. | |||
| Centers | − | ||
| The Sixth Affiliated Hospital of Sun Yat-Sen University | 226 (40.9) | − | |
| Cancer Hospital Chinese Academy of Medical Sciences | 175 (31.7) | − | |
| Liaoning Province Cancer Hospital & Institute | 151 (27.4) | − | |
| Peking University Cancer Hospital | − | 252 (100) | |
Age (
) (year)
|
55.5±11.5 | 55.2±11.7 | 0.918 |
| Sex | 0.665 | ||
| Male | 366 (66.3) | 171 (67.9) | |
| Female | 186 (33.7) | 81 (32.1) | |
| Pre-NCRT cT stage | 0.132 | ||
| cT3a/b | 288 (52.2) | 133 (52.8) | |
| cT3c | 211 (38.2) | 84 (33.3) | |
| cT3d | 53 (9.6) | 35 (13.9） | |
| Pre-NCRT cN stage | 0.835 | ||
| cN0 | 103 (18.7) | 51 (20.2) | |
| cN1 | 118 (21.3) | 55 (21.8) | |
| cN2 | 331 (60.0) | 146 (58.0) | |
| Pre-NCRT MRI EMVI | 0.901 | ||
| Negative | 377 (68.3) | 171 (67.8) | |
| Positive | 175 (31.7) | 81 (32.2) | |
Pre-NCRT CEA (ng/mL) (
)
|
8.1±18.0 | 8.2±18.6 | 0.977 |
| DTA (cm) | 0.564 | ||
| Upper (>10) | 18 (3.3) | 12 (4.8) | |
| Middle (6−10) | 252 (45.7) | 111 (44.0) | |
| Lower (0−5) | 282 (51.1) | 129 (51.2) | |
| Operation | 0.965 | ||
| Miles | 279 (50.6) | 128 (50.8) | |
| Dixon | 253 (45.8) | 114 (45.2) | |
| Hartmann | 20 (3.6) | 10 (4.0) | |
| Adjuvant chemotherapy | 0.817 | ||
| No | 294 (53.3) | 132 (52.4) | |
| Yes | 258 (46.7) | 120 (47.6) | |
| ypT stage | 0.975 | ||
| ypT0 | 112 (20.3) | 49 (19.4) | |
| ypT1 | 24 (4.3) | 12 (4.8) | |
| ypT2 | 154 (27.9) | 73 (29.0) | |
| ypT3 | 262 (47.5) | 118 (46.8) | |
| ypN stage | 0.781 | ||
| ypN0 | 401 (72.6) | 186 (73.8) | |
| ypN1 | 107 (19.4) | 44 (17.5) | |
| ypN2 | 44 (8.0) | 22 (8.7) | |
| DMRF (mm) | 0.624 | ||
| <7 | 484 (87.7) | 224 (88.9) | |
| ≥7 | 68 (12.3) | 28 (11.1) | |