Table 1. Patient characteristics of the European training (N = 2795) and the current clinical routine validation (N = 277) cohorts.
| Variable | Training cohort (N = 2235) | Current validation cohort (N = 277) | p-value |
|---|---|---|---|
| Sex | 0.780 | ||
| Male | 1575 (70.5) | 198 (71.5) | |
| Female | 660 (29.5) | 79 (28.5) | |
| Age, years | <0.001 | ||
| ≤49 | 290 (13.0) | 107 (38.6) | |
| 50–59 | 607 (27.2) | 78 (28.2) | |
| 60–69 | 917 (41.0) | 69 (24.9) | |
| ≥70 | 421 (18.8) | 23 (8.3) | |
| Tumor location | <0.001 | ||
| Low | 786 (35.2) | 116 (41.9) | |
| Mid | 1146 (51.3) | 158 (57.0) | |
| High | 303 (13.6) | 3 (1.1) | |
| cT stage | <0.001* | ||
| 2 | 18 (6.1) | 9 (3.2) | |
| 3 | 1887 (84.4) | 231 (83.4) | |
| 4 | 193 (8.6) | 37 (13.4) | |
| Treatments | |||
| Radiotherapy dose, Gy | <0.001 | ||
| <45Ɨ | 95 (4.3) | 20 (7.2) | |
| 45 | 1558 (69.7) | 39 (14.1) | |
| >45 | 582 (26.0) | 218 (78.7) | |
| Concomitant chemotherapy | <0.001 | ||
| No | 862 (38.6) | 5 (1.8) | |
| Yes | 1373 (61.4) | 272 (98.2) | |
| Surgery procedure | <0.001 | ||
| LAR | 1373 (61.4) | 100 (36.1) | |
| APR | 862 (38.6) | 177 (63.9) | |
| Adjuvant chemotherapy | <0.001 | ||
| No | 836 (37.4) | 15 (5.4) | |
| Yes | 1399 (62.6) | 262 (94.6) | |
| ypT stage | <0.001 | ||
| 0 | 205 (9.2) | 64 (23.1) | |
| 1–2 | 810 (36.2) | 88 (31.8) | |
| 3 | 1163 (52.0) | 119 (43.0) | |
| 4 | 57 (2.6) | 6 (2.2) | |
| ypN stage | 0.035 | ||
| 0 | 1551 (69.4) | 175 (63.2) | |
| 1–2 | 684 (30.6) | 102 (36.8) | |
| median follow-up time | 75 months | 26 months | - |
| 2y local control rate | 92.0% | 92.4% | 0.708 |
| 2y distant control rate | 77.8% | 79.8% | 0.431 |
| 2y overall survival | 88.3% | 93.7% | 0.833 |
Values in brackets are intra-variable categorical percentages
*
Fisher's exact test was used for cT stage.
Ɨ
Patients receiving < 45 Gy were all receiving long-course chemoradiation but not 25 Gy in 5 fractions.