Table 1. Baseline characteristics.
| Total | Liver metastasis | No liver metastasis | P value | |
|---|---|---|---|---|
| Number of patients | 1,470 (100.0) | 234 (15.9) | 1,236 (84.1) | |
| Age (years) | 63.7±11.0 | 63.4±11.9 | 63.7±10.9 | 0.739* |
| Male sex | 869 (59.1) | 125 (53.4) | 744 (60.2) | 0.059** |
| Pathology | 0.111** | |||
| Adenocarcinoma | 1,219 (82.9) | 191 (81.6) | 1,028 (83.2) | |
| Squamous cell carcinoma | 194 (13.2) | 34 (14.5) | 160 (12.9) | |
| NOS | 26 (1.8) | 5 (2.1) | 21 (1.7) | |
| Others | 31 (2.1) | 4 (1.7) | 27 (2.2) | |
| EGFR | 0.746** | |||
| Wild type | 670 (45.6) | 112 (47.9) | 558 (45.1) | |
| Mutation | 630 (42.9) | 96 (41.0) | 534 (43.2) | |
| Unknown | 170 (11.6) | 26 (11.1) | 144 (11.7) | |
| ALK | 0.064** | |||
| Wild type | 1,141 (77.6) | 175 (74.8) | 966 (78.2) | |
| Mutation | 94 (6.4) | 23 (9.8) | 71 (5.7) | |
| Unknown | 235 (16.0) | 36 (15.4) | 199 (16.1) | |
| PD-L1 | 0.794** | |||
| Negative | 210 (14.3) | 30 (12.8) | 180 (14.6) | |
| Positive | 618 (42.0) | 101 (43.2) | 517 (41.8) | |
| Unknown | 642 (43.7) | 103 (44.0) | 539 (43.6) | |
| Type of treatment (1st line) | 1.000** | |||
| Cytotoxic chemotherapy | 723 (49.2) | 115 (49.1) | 608 (49.2) | |
| Targeted therapy | 678 (46.1) | 108 (46.2) | 570 (46.1) | |
| Immunotherapy | 69 (4.7) | 11 (4.7) | 58 (4.7) |
*, t-test; **, Chi-square test. NOS, not otherwise specified; EGFR, epidermal growth factor receptor; ALK, anaplastic lymphoma kinase; PD-L1, programmed death-ligand 1.