Table 1.
Patient and treatment characteristics
| pMMR (N = 1099) | dMMR (N = 84) | p-value | |
|---|---|---|---|
| Sex, no. of male | 632 (58%) | 32 (38%) | < 0.01 |
| Age in years, mean (SD) | 61.1 (10.2) | 63.1 (11.7) | 0.14 |
| Sidedness | |||
| Left-sided | 443 (41%) | 14 (17%) | < 0.01 |
| Right-sided | 293 (27%) | 65 (78%) | |
| Rectosigmoid/rectum | 356 (32%) | 4 (5%) | |
| Missing | 7 | 1 | |
| Resection status of primary tumor | |||
| No resection | 57 (5%) | 1 (1%) | 0.17 |
| Resection | 1042 (95%) | 83 (99%) | |
| Differentation grade | |||
| Well | 22 (2%) | 0 (0%) | < 0.01 |
| Moderate | 885 (89%) | 37 (54%) | |
| Poor | 83 (8%) | 31 (46%) | |
| Missing | 109 | 16 | |
| T stage | |||
| T1–3 | 782 (72%) | 39 (47%) | < 0.01 |
| T4 | 301 (28%) | 44 (53%) | |
| Missing | 16 | 1 | |
| N stage | |||
| N0 | 344 (32%) | 28 (33%) | 0.83 |
| N1/2 | 746 (68%) | 56 (67%) | |
| Missing | 9 | 0 | |
| Stage | |||
| Stage I–III | 335 (30%) | 37 (45%) | 0.01 |
| Stage IV | 764 (70%) | 46 (55%) | |
| Missing | 0 | 1 | |
| WHO performance status | |||
| 0 | 331 (68%) | 17 (63%) | 0.88 |
| 1+ | 159 (32%) | 10 (37%) | |
| Missing | 609 | 57 | |
| Metastatic localization | |||
| Liver only | 769 (70%) | 23 (27%) | < 0.01 |
| Peritoneal involvement | 201 (18%) | 37 (44%) | |
| Other | 129 (12%) | 24 (29%) | |
| Number of metastatic sites | |||
| 1 | 878 (80%) | 72 (86%) | 0.41 |
| 2+ | 221 (20%) | 12 (14%) | |
| Molecular status | |||
| BRAFV600E mutation | 22 (4%) | 26 (50%) | < 0.01 |
| RAS mutation | 322 (52%) | 11 (21%) | |
| BRAFV600E and RAS wildtype | 274 (44%) | 15 (29%) | |
| Missing | 481 | 32 | |
| Lynch syndrome status | |||
| Probable Lynch | – | 21 (31%) | – |
| Sporadic | – | 46 (69%) | |
| Missing | – | 17 | |
| Local therapy | |||
| CRLM only | 769 (70%) | 23 (27%) | < 0.01 |
| CRS/HIPEC only | 172 (16%) | 40 (48%) | |
| Pulmonary metastasectomy only | 38 (3%) | 1 (1%) | |
| Lymph node resection only | 19 (2%) | 10 (12%) | |
| Other/combination* | 101 (9%) | 10 (12%) | |
| Systemic therapy | |||
| Neoadjuvant systemic therapy | 457 (42%) | 14 (17%) | < 0 .01 |
| Adjuvant systemic therapy after local therapy | 101 (9%) | 13 (15%) | |
| No perioperative systemic therapy | 541 (49%) | 57 (68%) | |
Bold-values are considered significant (p-value < 0.05)
CRLM colorectal liver metastases, CRS cytoreductive surgery, dMMR deficient mismatch repair, HIPEC hyperthermic intraperitoneal chemotherapy, mCRC metastatic colorectal cancer, pMMR proficient mismatch repair, SD standard deviation, WHO World Health Organization
*Other local treatment: metastasectomy of other organs (e.g., cerebral metastasectomy) or combination treatment (e.g., CRLM and CRS/HIPEC)