Table 1.
Patient characteristics.
| cohort A (n = 252) | cohort B (n = 298) | P-value* | |||
|---|---|---|---|---|---|
| Age, year | |||||
| Median (IQR) | 65 | (57–71) | 64 | (54–69) | 0.066 |
| ≥65 years, n (%) | 110 | (44) | 153 | (51) | 0.087 |
| Sex, n (%) | 0.543 | ||||
| Male | 144 | (57) | 179 | (60) | |
| Female | 108 | (43) | 119 | (40) | |
| Body mass index, n (%) | 0.417 | ||||
| <18.5 kg/m2 | 37 | (17) | 52 | (17) | |
| ≥18.5 kg/m2 | 215 | (83) | 246 | (83) | |
| ECOG PS, n (%) | <0.001 | ||||
| 0 | 124 | (49) | 99 | (33) | |
| 1 or 2 | 128 | (51) | 199 | (67) | |
| Primary tumor site, n (%) | 0.758 | ||||
| Right | 54 | (21) | 68 | (23) | |
| Left | 198 | (79) | 230 | (77) | |
| Surgery on primary tumor site, n (%) | |||||
| Yes | 45 | (18) | 74 | (25) | 0.061 |
| Pathologic type, n (%) | 0.334 | ||||
| Well-moderately differentiated adenocarcinoma | 226 | (90) | 268 | (90) | |
| Others | 14 | (5) | 22 | (7) | |
| Missing data | 12 | (5) | 8 | (3) | |
| RAS status, n (%) | 0.261 | ||||
| WT | 131 | (52) | 137 | (46) | |
| MT | 118 | (47) | 152 | (51) | |
| Missing data | 3 | (1) | 9 | (3) | |
| Metastatic organ site, n (%) | |||||
| Liver | 158 | (63) | 184 | (62) | 0.860 |
| Lung | 168 | (67) | 195 | (65) | 0.787 |
| Lymph node | 94 | (37) | 143 | (48) | 0.012 |
| Peritoneal dissemination | 30 | (12) | 72 | (24) | <0.001 |
| Bone | 17 | (7) | 36 | (12) | 0.049 |
| Number of metastatic organ site(s), n (%) | 0.055 | ||||
| 1 | 72 | (29) | 63 | (21) | |
| ≥2 | 180 | (71) | 235 | (79) | |
| Drug exposure, n (%) | 1.000 | ||||
| Fluoropyrimidine | 252 | (100) | 298 | (100) | |
| Oxaliplatin | 252 | (100) | 298 | (100) | |
| Irinotecan | 252 | (100) | 298 | (100) | |
| Bevacizumab | 252 | (100) | 298 | (100) | |
| Anti-EGFR antibody (in patients with wild type KRAS/NRAS tumors) | 131 | (100) | 137 | (100) | |
| Intolerable drug, n (%) | |||||
| Any drugs | 79 | (31) | 96 | (32) | 0.900 |
| Fluoropyrimidine | 4 | (2) | 22 | (7) | 0.003 |
| Oxaliplatin | 66 | (26) | 77 | (26) | 1.000 |
| Irinotecan | 8 | (3) | 28 | (9) | 0.006 |
| Bevacizumab | 11 | (4) | 31 | (10) | 0.013 |
| Anti-EGFR antibody (in patients with wild type KRAS/NRAS tumors) | 5 | (2) | 10 | (3) | 0.471 |
| Prior regimens, n (%) | 0.892 | ||||
| ≥3 | 125 | (50) | 145 | (49) | |
| Time since initiation of first-line chemotherapy, n (%) | 0.152 | ||||
| <18 months | 59 | (23) | 87 | (29) | |
| ≥18 months | 193 | (77) | 211 | (71) | |
| Baseline albumin, n (%) | |||||
| <3.5 g/dL | 72 | (29) | 172 | (58) | <0.001 |
| Missing | 6 | (2) | 9 | (3) | |
| Baseline serum AST, n (%) | |||||
| ≥40 IU/L | 50 | (20) | 107 | (36) | <0.001 |
| Missing data | 2 | (1) | 1 | (0.5) | |
| Baseline CRP, n (%) | |||||
| ≥1 mg/dL | 85 | (34) | 156 | (52) | <0.001 |
| Missing data | 7 | (3) | 9 | (3) | |
| Baseline serum CEA, n (%) | |||||
| ≥5 ng/mL | 218 | (87) | 270 | (91) | 0.253 |
| Missing data | 3 | (1) | 4 | (1) | |
*
P-values were calculated by Fisher's exact probability test for categorical variables.
IQR, interquartile range; EGFR, epidermal growth factor receptor; RAS, rat sarcoma; AST, aspartate transaminase; CEA, carcinoembryonic antigen; WT, wild-type; MT, mutant.