Table 3.
Characteristics of the stage IV patients receiving first-line EGFR TKIs.
| Characteristics | EGFR Mutation Test Results in Liquid/Tissue Biopsy | p Value | |
|---|---|---|---|
| Concordant (n = 31) | Discordant (n = 9) | ||
| Sex | 0.4546 | ||
| Female | 20 (65%) | 7 (78%) | |
| Male | 11 (35%) | 2 (22%) | |
| Age (year) | 63.4 ± 10 | 63.0 ± 9.9 | 0.9192 |
| Age: | 0.5825 | ||
| <65 years | 14 (45%) | 5 (56%) | |
| ≥65 years | 17 (55%) | 4 (44%) | |
| Performance status: | 0.3393 | ||
| ECOG 0–1 | 30 (97%) | 8 (89%) | |
| ECOG 2–4 | 1 (3%) | 1 (11%) | |
| Advanced primary tumor (T3–4) | 25 (81%) | 5 (56%) | 0.1260 |
| Lymph node involvement (N1–3) | 26 (84%) | 3 (33%) | 0.0028 |
| Metastasis (M1) | 31 (100%) | 9 (100%) | 0.0401 |
| Metastasis to: | |||
| Brain | 11 (35%) | 0 (0%) | 0.0358 |
| Lung | 11 (35%) | 5 (56%) | 0.2792 |
| Bone | 19 (61%) | 2 (22%) | 0.0388 |
| Pleural space | 17 (55%) | 6 (67%) | 0.5274 |
| Liver | 5 (16%) | 1 (11%) | 0.7105 |
| Pericardial space | 7 (23%) | 0 (0%) | 0.1165 |
| Adrenal gland | 5 (16%) | 1 (11%) | 0.7105 |
| Other site | 4 (13%) | 0 (0%) | 0.2560 |
| Mutation site: | |||
| Exon 18 | 1 (3%) | 0 (0%) | 0.5853 |
| Exon 19 | 16 (52%) | 6 (67%) | 0.4242 |
| Exon 21 | 14 (45%) | 3 (33%) | 0.5274 |
| TKI used: | 0.0243 | ||
| Gefitinib | 6 (19%) | 2 (22%) | |
| Erlotinib | 18 (58%) | 1 (11%) | |
| Afatinib | 7 (23%) | 6 (67%) | |
| Initial treatment response: | 0.4320 | ||
| Partial response (PR) | 18 (58%) | 5 (56%) | |
| Stable disease (SD) | 9 (29%) | 4 (44%) | |
| Progressive disease (PD) | 4 (13%) | 0 (0%) | |
| Objective response rate | 18 (58%) | 5 (56%) | 0.8934 |
| Disease control rate | 27 (87%) | 9 (100%) | 0.2560 |
Data were presented as mean ± standard deviation or number (percentage). Abbreviations: EGFR = epidermal growth factor receptor; ECOG = Eastern Cooperative Oncology Group; TKI = tyrosine kinase inhibitors.