Table 1. Patient characteristics according to MMR status.
| Number of eligible patients | Group 1 pMMR (n=497) | Group 2 dMMR MLH1 hypermethylation (n=13) | Group 3 dMMR no MLH1 hypermethylation (n=5) | P-value# (1 vs 2) | P-value# (2 vs 3) |
|---|---|---|---|---|---|
| Age | |||||
| ⩽50 years | 51 (10%) | 0 (0%) | 2 (40%) | ||
| Median (range) | 63 (31–81) | 70 (54–78) | 57 (35–64) | 0.053 | 0.0051 |
| Gender | |||||
| Male | 315 (63%) | 7 (54%) | 4 (80%) | 0.49 | 0.29 |
| Location of the primary tumour | |||||
| Colon—left | 164 (33%) | — | — | <0.0001 | — |
| Colon—right | 122 (25%) | 13 (100%) | 5 (100%) | ||
| Rectosigmoid | 30 (6%) | — | — | ||
| Rectum | 161 (32%) | — | — | ||
| Unknown | 20 (4%) | — | — | ||
| Histology of primary tumour | |||||
| Adenocarcinoma | 438 (88%) | 10 (77%) | 2 (40%) | 0.10 | 0.14 |
| Mucinous adenocarcinoma | 38 (8%) | 3 (23%) | 3 (60%) | ||
| Adenosquamous carcinoma | 4 (<1%) | — | — | ||
| Undifferentiated carcinoma | 3 (<1%) | — | — | ||
| Unknown | 14 (3%) | — | — | ||
| Differentiation grade | |||||
| Well/moderate | 259 (52%) | 3 (23%) | 2 (40%) | 0.025 | 0.48 |
| Poor/undifferentiated | 222 (45%) | 10 (77%) | 3 (60%) | ||
| Unknown | 16 (3%) | — | — | ||
| Diagnosis of metastases | |||||
| <12 months before randomization | 292 (59%) | 8 (62%) | 1 (20%) | 0.84 | 0.11 |
| < 6 months before randomization | 244 (49%) | 7 (54%) | 1 (20%) | 0.77 | 0.18 |
| Number of sites involved | |||||
| 1 site of metastases | 241 (48%) | 7 (54%) | 1 (20%) | 0.73 | 0.18 |
| >1 site of metastases | 250 (50%) | 6 (46%) | 4 (80%) | ||
| Unknown | 6 (1%) | — | — | ||
| Primary tumour involved at start chemotherapy | 62 (12%) | 3 (15%) | 2 (40%) | 0.37 | 0.54 |
| Previous adjuvant therapy | 82 (17%) | 2 (15%) | 2 (40%) | 0.91 | 0.28 |
| Resection of primary tumour | 488 (98%) | 13 (100%) | 5 (100%) | 0.49 | — |
#P-value logistic regression.