Table 1.
Patient characteristics in the overall population
| Features | Available | Anti-PD-1-exposed group (n=67) | Anti-PD-1-naive group (n=166) | P value |
| Age, ≥65 years, n (%) | 46 (68.7) | 113 (68.1) | 1.00 | |
| Male, n (%) | 43 (64.2) | 122 (73.5) | 0.20 | |
| ECOG PS, n (%) | ||||
| 0 | 49 (73.1) | 119 (71.7) | 0.58 | |
| 1 | 16 (23.9) | 45 (27.1) | ||
| 2 | 2 (3.0) | 2 (1.2) | ||
| Previous treatment regimens, n (%) | ||||
| 1 | 31 (46.3) | 123 (74.1) | <0.001 | |
| ≥2 | 36 (53.7) | 43 (25.9) | ||
| Organs with metastases, n (%) | ||||
| ≤2 | 55 (82.1) | 138 (83.1) | 0.85 | |
| ≥3 | 12 (17.9) | 28 (16.9) | ||
| Site of metastases, n (%) | ||||
| Liver | 25 (37.3) | 57 (34.3) | 0.76 | |
| Lung | 5 (7.5) | 25 (15.1) | 0.14 | |
| Peritoneum | 36 (53.7) | 77 (46.4) | 0.32 | |
| Lymph node | 58 (86.6) | 139 (83.7) | 0.69 | |
| Other | 5 (7.5) | 27 (16.3) | 0.093 | |
| HER2, n (%) | 228 | |||
| Negative | 62 (93.9) | 136 (84.0) | 0.051 | |
| Positive | 4 (6.1) | 26 (16.0) | ||
| MMR, n (%) | 212 | |||
| Proficient | 56 (96.6) | 143 (92.9) | 0.52 | |
| Deficient | 2 (3.4) | 11 (7.1) | ||
| EBV, n (%) | 215 | |||
| Negative | 55 (91.7) | 154 (99.4) | 0.007 | |
| Positive | 5 (8.3) | 1 (0.6) | ||
| PD-L1 CPS, n (%) | 211 | |||
| <1 | 11 (18.6) | 22 (14.5) | 0.53 | |
| ≥1 | 48 (81.4) | 130 (85.5) | ||
| PD-L1 CPS, n (%) | 211 | |||
| <10 | 49 (84.5) | 135 (88.2) | 0.49 | |
| ≥10 | 9 (15.5) | 18 (11.8) | ||
| Response to first line chemotherapy | 194 | |||
| ORR (%) | 51.8 | 50.0 | 0.88 | |
| DCR (%) | 76.8 | 79.0 | 0.85 | |
| Median PFS (month) | 6.3 (95% CI 5.5 to 7.2) | 6.7 (95% CI 5.7 to 7.7) | 0.18 |
CPS, combined positive score; DCR, disease control rate; EBV, Epstein-Barr virus; ECOG PS, Eastern Cooperative Oncology Group performance status; HER2, human epidermal growth factor receptor related 2; MMR, mismatch repair; ORR, objective response rate; PD-L1, programmed death-ligand 1; PFS, progression-free survival; TC, tumour cell.