Table 1.
Baseline characteristics of patients
| Characteristics | All (n = 588) | Univariate | Multivariate | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Re‐biopsy | Liquid biopsy | ||||||||
| Re‐biopsy | Liquid biopsy | No biopsy | P | HR | P | HR | P | ||
| Age (years) | 1.046 | 0.847 | 0.660 | 0.220 | |||||
| ≤ 65 | 379 (68.3) | 208 (67.5) | 87 (73.7) | 84 (65.1) | 0.318 | ||||
| > 65 | 176 (31.7) | 100 (32.5) | 31 (26.3) | 45 (34.9) | |||||
| Gender | 0.889 | 0.674 | 1.557 | 0.135 | |||||
| Male | 226 (40.7) | 126 (40.9) | 50 (42.4) | 50 (38.8) | 0.842 | ||||
| Female | 329 (59.3) | 182 (59.1) | 68 (57.6) | 79 (61.2) | |||||
| Smoking | 0.893 | 0.731 | 1.066 | 0.875 | |||||
| Non‐smoker | 438 (78.9) | 242 (78.6) | 94 (79.7) | 102 (79.1) | 0.969 | ||||
| Current or former smoker | 117 (21.1) | 66 (21.4) | 24 (20.3) | 27 (20.9) | |||||
| ECOG | 0.728 | 0.365 | 0.907 | 0.824 | |||||
| 0–1 | 494 (89.0) | 268 (87.0) | 111 (94.1) | 115 (89.1) | 0.114 | ||||
| 2–3 | 61 (11.0) | 40 (13.0) | 7 (5.9) | 14 (10.9) | |||||
| Histology | 0.986 | 0.969 | 1.854 | 0.219 | |||||
| Adenocarcinoma | 496 (89.4) | 276 (89.6) | 105 (89.0) | 115 (89.1) | 0.978 | ||||
| Non‐adenocarcinoma | 59 (10.6) | 32 (10.4) | 13 (11.0) | 14 (10.9) | |||||
| Gene mutation type | |||||||||
| 19del | 292 (52.6) | 178 (57.8) | 54 (45.8) | 60 (46.5) | 0.096 | 4.306 | 0.130 | 0.955 | 0.964 |
| L858R | 245 (44.1) | 121 (39.3) | 59 (50.0) | 65 (50.4) | 3.090 | 0.241 | 1.304 | 0.795 | |
| Other | 11 (2.0) | 7 (2.3) | 3 (2.5) | 1 (0.8) | 11.029 | 0.095 | 4.394 | 0.336 | |
| Double mutation | 7 (1.3) | 2 (0.6) | 2 (1.7) | 3 (2.3) | |||||
| EGFR‐TKIs | |||||||||
| Gefitinib | 344 (62.0) | 198 (64.3) | 72 (61.0) | 74 (57.4) | 0.63 | 1.729 | 0.476 | 1.025 | 0.977 |
| Erlotinib | 103 (18.6) | 58 (18.8) | 18 (15.3) | 27 (20.9) | 1.234 | 0.789 | 0.740 | 0.738 | |
| Icotinib | 97 (17.5) | 47 (15.3) | 25 (21.2) | 25 (19.4) | 1.188 | 0.828 | 1.093 | 0.921 | |
| 2‐TKIs | 11 (2.0) | 5 (1.6) | 3 (2.5) | 3 (2.3) | |||||
| Line of EGFR‐TKIs | 0.752 | 0.279 | 1.208 | 0.570 | |||||
| 1 | 410 (73.9) | 221 (71.8) | 93 (78.8) | 96 (74.4) | 0.328 | ||||
| ≥ 2 | 145 (26.1) | 87 (28.2) | 25 (21.2) | 33 (25.6) | |||||
| Efficacy of EGFR‐TKIs | |||||||||
| PR | 277 (49.9) | 163 (52.9) | 70 (59.3) | 44 (34.1) | <0.001 | 1.032 | 0.953 | 1.652 | 0.452 |
| SD | 214 (38.6) | 112 (36.4) | 42 (35.6) | 60 (46.5) | 0.507 | 0.205 | 0.698 | 0.592 | |
| PD | 36 (6.5) | 15 (4.9) | 1 (0.8) | 20 (15.5) | 0.211 | 0.013 | 0.044 | 0.010 | |
| Not clear | 28 (5.0) | 18 (5.8) | 5 (4.2) | 5 (3.9) | |||||
Non‐adenocarcinoma included: 26 non‐small cell lung cancer (NSCLC), 15 adenosquamous carcinoma, 12 squamous carcinoma, 4 poorly differentiated adenocarcinoma, and 2 large cell lung cancer. Other included 5 G719X, 3 L861Q, and 3 S768I. Double mutation included five 19del and L858R, one 19 del and L861Q, and one S768I and G719X. ECOG, Eastern Cooperative Oncology Group; PD, progressive disease; PR, partial response; SD, stable disease; TKI, tyrosine kinase inhibitor.