Table 1 Baseline features of patients with or without brain metastasis
|  | Total (n = 308, %) | BrM (n = 83, %) | No BrM (n = 225, %) | P value |
|---|---|---|---|---|
Median age, years (range) | 62 (20–89) | 58 (32–76) | 63 (20–89) |  |
Sex | Â | Â | Â | Â |
 Male | 246 (79.9) | 62 (74.7) | 184 (81.8) | 0.1692 |
 Female | 62 (20.1) | 21 (25.3) | 41 (18.2) |  |
Smoking history | Â | Â | Â | Â |
 Current/former | 189 (61.4) | 45 (54.2) | 144 (64.0) | 0.1177 |
 Never | 119 (38.6) | 38 (45.8) | 81 (36.0) |  |
ECOG PS | Â | Â | Â | Â |
 0–1 | 282 (91.6) | 73 (88.0) | 209 (92.9) | 0.1667 |
 2 | 26 (8.4) | 10 (12.0) | 16 (7.1) |  |
Pathology | Â | Â | Â | Â |
 Adenocarcinoma | 194 (63.0) | 66 (79.5) | 128 (56.9) | 0.0003 |
 Squamous carcinoma | 79 (25.6) | 9 (10.8) | 70 (31.1) |  |
 Others | 35 (11.4) | 8 (9.6) | 27 (12.0) |  |
Driver gene alterations detection | Â | Â | Â | Â |
 EGFR | 28 (9.1) | 12 (14.5) | 16 (7.1) |  |
 ALK/ROS1/RET | 4 (1.3) | 0 (0.0) | 4 (1.8) |  |
 KRAS | 33 (10.7) | 8 (9.6) | 25 (11.1) |  |
 BRAF | 3 (1.0) | 2 (2.4) | 1 (0.4) |  |
 HER2 | 5 (1.6) | 2 (2.4) | 3 (1.3) |  |
 Wild type | 137 (44.5) | 41 (49.4) | 96 (42.7) | 0.7500 |
 Unknown | 98 (31.8) | 18 (21.7) | 80 (35.6) |  |
PD-L1 expression (IHC) | Â | Â | Â | Â |
 Positive | 117 (80.7) | 21 (80.7) | 96 (80.7) | 0.7927 |
 Negative | 28 (19.3) | 5 (19.3) | 23 (19.3) |  |
 Unknown | 163 | 57 | 106 |  |
Liver Metastasis | Â | Â | Â | Â |
 Yes | 269 (87.3) | 69 (83.1) | 200 (88.9) | 0.1777 |
 No | 39 (12.7) | 14 (16.9) | 25 (11.1) |  |
Corticosteroid use before ICI | Â | Â | Â | Â |
 Yes | 102 (33.1) | 27 (32.5) | 75 (33.3) | 0.8943 |
 No | 206 (66.9) | 56 (67.5) | 150 (66.7) |  |
Symptoms at start of ICI | Â | Â | Â | Â |
 Asymptomatic BrM | - | 50 (60.2) | - |  |
 Symptomatic BrM | - | 33 (39.8) | - |  |
Treatment strategy | Â | Â | Â | Â |
 ICI alone | 156 (50.6) | 33 (39.8) | 123 (54.7) | 0.0202 |
 ICI + chemotherapy | 94 (30.5) | 31 (37.3) | 63 (28.0) |  |
 ICI + anti-angiogenic therapy | 51 (16.6) | 14 (16.9) | 37 (16.4) |  |
 ICI + chemotherapy + anti-angiogenic therapy | 7 (2.3) | 5 (6.0) | 2 (0.9) |  |
ICI treatment line | Â | Â | Â | Â |
 1 | 83 (26.9) | 21 (25.3) | 62 (27.6) | 0.6924 |
 2 | 124 (40.3) | 24 (28.9) | 100 (44.4) |  |
 3 | 64 (20.8) | 19 (22.9) | 45 (20.0) |  |
 >3 | 37 (12.0) | 19 (22.9) | 18 (8.0) |  |
Systemic response | Â | Â | Â | Â |
 PR | 81 (26.3) | 15 (18.1) | 66 (29.3) | 0.0464 |
 SD | 127 (41.2) | 37 (44.6) | 90 (40.0) | 0.2664 |
 PD | 89 (28.9) | 23 (27.7) | 66 (29.3) |  |
 NE | 11 (3.6) | 8 (9.6) | 3 (1.3) |  |
BrM, brain metastasis; ECOG PS, Eastern Cooperative Oncology Group performance status; ICI, immune checkpoint inhibitor; IHC, immunohistochemistry; PR, partial response; SD, stable disease; PD, disease progression | ||||