Table 1.
Baseline characteristics of the study cohort.
| Variables | All Patients | Gefitinib | Erlotinib | Afatinib | Osimertinib | p-Value |
|---|---|---|---|---|---|---|
| n | 186 | 27 | 104 | 48 | 7 | |
| Sex | ||||||
| Female | 123 (66%) | 16 (59%) | 71 (68%) | 30 (63%) | 6 (86%) | 0.5197 |
| Male | 63 (34%) | 11 (41%) | 33 (32%) | 18 (38%) | 1 (14%) | |
| Age (years) | 65.5 ± 11.2 | 64.9 ± 13.2 | 66.5 ± 10.7 | 63.3 ± 10.6 | 68.9 ± 13.6 | 0.3470 |
| <65 | 92 (49%) | 16 (59%) | 47 (45%) | 26 (54%) | 3 (43%) | 0.5044 |
| ≥65 | 94 (51%) | 11 (41%) | 57 (55%) | 22 (46%) | 4 (57%) | |
| ECOG performance status | ||||||
| 0–1 | 159 (85%) | 23 (85%) | 90 (87%) | 42 (88%) | 4 (57%) | 0.1884 |
| ≥2 | 27 (15%) | 4 (15%) | 14 (13%) | 6 (13%) | 3 (43%) | |
| Karnofsky performance status | ||||||
| 100 | 12 (6%) | 3 (11%) | 7 (7%) | 1 (2%) | 1 (14%) | 0.2980 |
| 90 | 21 (11%) | 4 (15%) | 9 (9%) | 8 (17%) | 0 (0%) | |
| 80 | 125 (67%) | 16 (59%) | 74 (71%) | 32 (67%) | 3 (43%) | |
| 70 | 27 (15%) | 4 (15%) | 14 (13%) | 6 (13%) | 3 (43%) | |
| ≤60 | 1 (1%) | 0 (0%) | 0 (0%) | 1 (2%) | 0 (0%) | |
| EGFR mutation | ||||||
| Exon 19 deletion | 85 (46%) | 10 (37%) | 46 (44%) | 25 (52%) | 4 (57%) | 0.5591 |
| Exon 21 L858R | 102 (55%) | 17 (63%) | 59 (57%) | 23 (48%) | 3 (43%) | 0.5311 |
| PD-L1 † | ||||||
| <1% | 29 (29%) | 1 (33%) | 16 (24%) | 12 (43%) | 0 (0%) | 0.1701 |
| ≥1% | 72 (71%) | 2 (67%) | 50 (76%) | 16 (57%) | 4 (100%) | |
| Number of brain metastases | ||||||
| 1 | 63 (34%) | 15 (56%) | 31 (30%) | 15 (31%) | 2 (29%) | 0.0378 |
| 2–4 | 55 (30%) | 10 (37%) | 30 (29%) | 14 (29%) | 1 (14%) | |
| ≥5 | 68 (37%) | 2 (7%) | 43 (41%) | 19 (40%) | 4 (57%) | |
| Number of ECM sites | ||||||
| 0 | 25 (13%) | 4 (15%) | 15 (14%) | 6 (13%) | 0 (0%) | 0.6122 |
| 1–2 | 91 (49%) | 14 (52%) | 45 (43%) | 28 (58%) | 4 (57%) | |
| ≥3 | 70 (38%) | 9 (33%) | 44 (42%) | 14 (29%) | 3 (43%) | |
| Site of ECMs | ||||||
| Lung metastasis | 99 (53%) | 12 (44%) | 58 (56%) | 25 (52%) | 4 (57%) | 0.7590 |
| Pleural metastasis/effusion | 81 (44%) | 12 (44%) | 49 (47%) | 17 (35%) | 3 (43%) | 0.6064 |
| Bone metastasis | 116 (62%) | 18 (67%) | 63 (61%) | 30 (63%) | 5 (71%) | 0.8965 |
| Liver metastasis | 26 (14%) | 1 (4%) | 16 (15%) | 7 (15%) | 2 (29%) | 0.2844 |
| Pericardial metastasis/effusion | 51 (27%) | 6 (22%) | 31 (30%) | 11 (23%) | 3 (43%) | 0.5741 |
| Adrenal metastasis | 23 (12%) | 2 (7%) | 15 (14%) | 5 (10%) | 1 (14%) | 0.7504 |
| Other metastasis | 12 (6%) | 4 (15%) | 6 (6%) | 1 (2%) | 1 (14%) | 0.1424 |
| GPA (version 2010) score | ||||||
| ≥2.5 | 26 (14%) | 7 (26%) | 11 (11%) | 8 (17%) | 0 (0%) | 0.2945 |
| 1.5–2.0 | 66 (35%) | 11 (41%) | 37 (36%) | 15 (31%) | 3 (43%) | |
| ≤1.0 | 94 (51%) | 9 (33%) | 56 (54%) | 25 (52%) | 4 (57%) | |
| GPA (version 2017) score | ||||||
| ≥2.5 | 36 (19%) | 8 (30%) | 18 (17%) | 10 (21%) | 0 (0%) | 0.0552 |
| 1.5–2.0 | 120 (65%) | 19 (70%) | 65 (63%) | 32 (67%) | 4 (57%) | |
| ≤1.0 | 30 (16%) | 0 (0%) | 21 (20%) | 6 (13%) | 3 (43%) | |
| GPA (version 2022) score | ||||||
| ≥3.0 | 17 (9%) | 3 (11%) | 10 (10%) | 4 (8%) | 0 (0%) | 0.1905 |
| 1.5–2.5 | 149 (80%) | 24 (89%) | 79 (76%) | 41 (85%) | 5 (71%) | |
| ≤1.0 | 20 (11%) | 0 (0%) | 15 (14%) | 3 (6%) | 2 (29%) | |
| Anti-VEGF treatment | ||||||
| No | 175 (94%) | 27 (100%) | 95 (91%) | 47 (98%) | 6 (86%) | 0.1545 |
| Yes | 11 (6%) | 0 (0%) | 9 (9%) | 1 (2%) | 1 (14%) | |
| Brain OP (operation for brain tumor) | ||||||
| No | 136 (73%) | 16 (59%) | 80 (77%) | 33 (69%) | 7 (100%) | 0.0919 |
| Yes | 50 (27%) | 11 (41%) | 24 (23%) | 15 (31%) | 0 (0%) | |
| Brain RT (radiotherapy for brain tumor) | ||||||
| No | 125 (67%) | 14 (52%) | 80 (77%) | 24 (50%) | 7 (100%) | 0.0006 |
| Yes | 61 (33%) | 13 (48%) | 24 (23%) | 24 (50%) | 0 (0%) |
Abbreviations: ECOG, Eastern Cooperative Oncology Group; EGFR, epidermal growth factor receptor; ECM, extracranial metastasis; GPA, graded prognostic assessment; OP, surgery for brain tumor; PD-L1, programmed death ligand 1; RT, radiotherapy for brain tumor; TKI, tyrosine kinase inhibitor; VEGF, vascular endothelial growth factor. Data are presented as n (%) or mean ± standard deviation. p-values are presented for the results of the chi-squared test or the analysis of variance. † PD-L1 was examined in 101 patients.