Patients and disease characteristics in the developing and validating set
| Characteristics | Developing set N=163 (%) | Validating set N=146 (%) | P value* |
| Age (years) | 0.171 | ||
| Median (IQR) | 61 (48.5–70.5) | 59 (46–69) | |
| Sex | 0.909 | ||
| Female | 73 (44.8) | 67 (45.9) | |
| Male | 90 (55.2) | 79 (54.1) | |
| Baseline ECOG PS | <0.001 | ||
| 0 | 99 (60.7) | 58 (39.7) | |
| ≥1 | 64 (39.3) | 88 (60.3) | |
| Primary tumor sidedness | 0.223 | ||
| Left | 47 (28.8) | 52 (35.6) | |
| Right | 116 (71.2) | 94 (64.4) | |
| RAS and BRAF mutational status | 0.113 | ||
| All wild type | 61 (37.4) | 55 (40.1) | |
| RAS mutated | 48 (29.4) | 51 (37.2) | |
| BRAF mutated | 54 (33.1) | 31 (22.6) | |
| Primary tumor resection | <0.001 | ||
| No | 4 (2.5) | 53 (36.3) | |
| Yes | 159 (97.5) | 93 (63.7) | |
| Histology mucinous | <0.001 | ||
| No | 75 (46) | 94 (64.4) | |
| Yes | 88 (54) | 50 (34.2) | |
| Adjuvant treatment | 0.109 | ||
| No | 95 (58.3) | 71 (48.6) | |
| Yes | 68 (41.7) | 75 (51.4) | |
| NLR | 1 | ||
| Median (IQR) | 3.2 (2.3–4.85) | 3.04 (1.95–4.98) | |
| NLR | 1 | ||
| ≤3 | 80 (49.1) | 71 (48.6) | |
| >3 | 83 (50.9) | 75 (51.4) | |
| Platelets | 0.579 | ||
| Median (IQR) | 253 (191.5–339.5) | 249 (191.8–316.5) | |
| Metastases presentation | 0.111 | ||
| Metachronous | 76 (46.6) | 82 (56.2) | |
| Synchronous | 87 (53.4) | 64 (43.8) | |
| Number of metastatic sites | 0.005 | ||
| 0–1 | 66 (40.5) | 81 (55.5) | |
| 2 | 50 (30.7) | 44 (30.1) | |
| ≥3 | 47 (28.8) | 21 (14.4) | |
| Liver metastases | 0.555 | ||
| No | 107 (65.6) | 91 (62.3) | |
| Yes | 56 (34.4) | 55 (37.7) | |
| Bone metastases | 1 | ||
| No | 153 (93.9) | 137 (93.8) | |
| Yes | 10 (6.1) | 9 (6.2) | |
| Lung metastases | 0.069 | ||
| No | 122 (74.8) | 122 (83.6) | |
| Yes | 41 (25.2) | 24 (16.4) | |
| Peritoneal metastases | 0.194 | ||
| No | 97 (59.5) | 98 (67.1) | |
| Yes | 66 (40.5) | 48 (32.9) | |
| Brain metastases | 1 | ||
| No | 161 (98.8) | 145 (99.3) | |
| Yes | 2 (1.2) | 1 (0.7) | |
| Lymph nodes metastases | 0.048 | ||
| No | 56 (34.4) | 67 (45.9) | |
| Yes | 107 (65.6) | 79 (54.1) | |
| Previous chemotherapy for metastatic disease | 1 | ||
| No | 37 (22.7) | 33 (22.6) | |
| Yes | 126 (77.3) | 113 (77.4) | |
| Number of prior lines for metastatic disease | <0.001 | ||
| 0 | 37 (22.7) | 69 (47.3) | |
| 1 | 60 (36.8) | 31 (21.2) | |
| 2 | 31 (19) | 24 (16.4) | |
| ≥3 | 35 (21.5) | 22 (15.1) | |
| ICI line | 0.454 | ||
| First | 37 (22.7) | 42 (28.8) | |
| Second | 61 (37.4) | 48 (32.9) | |
| Third or more | 65 (39.9) | 56 (38.4) | |
| Regimen | 0.261 | ||
| Anti-CTLA-4+anti-PD-1 | 53 (32.5) | 38 (26.0) | |
| Anti-PD-(L)1 | 110 (67.5) | 108 (74.0) |
*Fisher’s exact test or Wilcoxon-Mann-Whitney test, as appropriate.
CTLA-4, cytotoxic T-lymphocyte antigen 4; ECOG PS, Eastern Cooperative Oncology Group Performance Status; NLR, neutrophil-to-lymphocyte ratio; PD-(L)1, programmed death (ligand)1.