Table 1.
Characteristics of the study population distinguished by body mass index
| Characteristic | Total (N = 820) | Body mass index categories | ||||
|---|---|---|---|---|---|---|
| Underweight (N = 71) | Normal (N = 343) | Overweight (N = 200) | Obese (N = 206) | P | ||
| Age, years | 64.3 (10.4) | 63.4 (11.5) | 64.3 (10.8) | 65.2 (10.2) | 63.6 (9.7) | 0.404 |
| Sex | 0.282 | |||||
| Men | 630 (76.8) | 51 (71.8) | 256 (74.6) | 161 (80.5) | 162 (78.6) | |
| Women | 190 (23.2) | 20 (28.2) | 87 (25.4) | 39 (19.5) | 44 (21.4) | |
| Smoking status | 0.289 | |||||
| Never | 213 (26.0) | 20 (28.2) | 100 (29.2) | 43 (21.5) | 50 (24.3) | |
| Ever | 606 (73.9) | 51 (71.8) | 243 (70.8) | 156 (78.0) | 156 (75.7) | |
| Unknown | 1 (0.1) | 0 (0.0) | 0 (0.0) | 1 (0.5) | 0 (0.0) | |
| ECOG PS, ≥2 | 93 (11.3) | 17 (23.9) | 49 (14.3) | 14 (7.0) | 13 (6.3) | <0.001 |
| Charlson comorbidity index, ≥2 | 95 (11.6) | 8 (11.3) | 39 (11.4) | 22 (11.0) | 26 (12.6) | 0.959 |
| Neutrophil‐to‐lymphocyte ratio | 5.39 (6.65) | 7.82 (8.79) | 6.05 (7.48) | 4.71 (5.16) | 4.13 (5.10) | <0.001 |
| Histology, squamous cell carcinoma | 218 (26.6) | 19 (26.8) | 84 (24.5) | 53 (26.5) | 62 (30.1) | 0.557 |
| PD‐L1 expression status | 0.956 | |||||
| Tumour proportion score < 50% | 342 (41.7) | 30 (42.3) | 146 (42.6) | 79 (39.5) | 87 (42.2) | |
| Tumour proportion score ≥ 50% | 299 (36.5) | 27 (38.0) | 127 (37.0) | 74 (37.0) | 71 (34.5) | |
| Unknown | 179 (21.8) | 14 (19.7) | 70 (20.4) | 47 (23.5) | 48 (23.3) | |
| Treatment agents | 0.126 | |||||
| Atezolizumab | 271 (33.0) | 20 (28.2) | 112 (32.7) | 61 (30.5) | 78 (37.9) | |
| Pembrolizumab | 417 (50.9) | 40 (56.3) | 165 (48.1) | 115 (57.5) | 97 (47.1) | |
| Nivolumab | 132 (16.1) | 11 (15.5) | 66 (19.2) | 24 (12.0) | 31 (15.0) | |
| Line of treatment | 0.152 | |||||
| 1 | 153 (18.7) | 15 (21.1) | 68 (19.8) | 45 (22.5) | 25 (12.1) | |
| 2 | 359 (43.8) | 28 (39.4) | 156 (45.5) | 80 (40.0) | 95 (46.1) | |
| 3 | 197 (24.0) | 16 (22.5) | 72 (21.0) | 54 (27.0) | 55 (26.7) | |
| ≥4 | 111 (13.5) | 12 (16.9) | 47 (13.7) | 21 (10.5) | 31 (15.0) | |
Values are presented as n (%) or mean (standard deviation).
ECOG PS, European Cooperative Oncology Group Performance Status; PD‐L1, programmed death ligand 1.