Table 2. Baseline characteristics of the training and validation cohorts.
| Characteristic | Variable | Training cohort (n=3,444) | Validation cohort (n=1,476) |
|---|---|---|---|
| Age, years | ≤65 | 1,827 (53.0) | 805 (54.5) |
| 66–71 | 714 (20.7) | 297 (20.1) | |
| >71 | 903 (26.2) | 374 (25.3) | |
| Sex | Male | 1,875 (54.4) | 802 (54.3) |
| Female | 1,569 (45.6) | 674 (45.7) | |
| Race | White | 2,679 (77.8) | 1,153 (78.1) |
| Black | 419 (12.2) | 158 (10.7) | |
| Other | 346 (10.0) | 165 (11.2) | |
| Marital | Married | 1,833 (53.2) | 849 (57.5) |
| Unmarried | 1,611 (46.8) | 627 (42.5) | |
| Grade | I | 125 (3.6) | 63 (4.3) |
| II | 908 (26.4) | 352 (23.8) | |
| III | 2,305 (66.9) | 1,020 (69.1) | |
| IV | 106 (3.1) | 41 (2.8) | |
| Tumor size, mm | ≤46 | 1,592 (46.2) | 695 (47.1) |
| 47–70 | 1,055 (30.6) | 460 (31.2) | |
| >70 | 797 (23.1) | 321 (21.7) | |
| Histology | LUAD | 2,270 (65.9) | 967 (65.5) |
| ADSQC | 61 (1.8) | 22 (1.5) | |
| SQCC | 547 (15.9) | 223 (15.1) | |
| LCLC | 50 (1.5) | 28 (1.9) | |
| Other | 516 (15.0) | 236 (16.0) | |
| T | T1 | 341 (9.9) | 151 (10.2) |
| T2 | 1,051 (30.5) | 469 (31.8) | |
| T3 | 939 (27.3) | 404 (27.4) | |
| T4 | 1,113 (32.3) | 452 (30.6) | |
| N | N0 | 831 (24.1) | 349 (23.6) |
| N1 | 338 (9.8) | 150 (10.2) | |
| N2 | 1,656 (48.1) | 730 (49.5) | |
| N3 | 619 (18.0) | 247 (16.7) | |
| Surgery | No | 3,248 (94.3) | 1,379 (93.4) |
| Yes | 196 (5.7) | 97 (6.6) | |
| Radiation | No/Unknown | 737 (21.4) | 325 (22.0) |
| Yes | 2,707 (78.6) | 1,151 (78.0) | |
| Chemotherapy | No/Unknown | 1,495 (43.4) | 656 (44.4) |
| Yes | 1,949 (56.6) | 820 (55.6) | |
| Bone metastasis | No | 2,368 (68.8) | 1,066 (72.2) |
| Yes | 1,076 (31.2) | 410 (27.8) | |
| Liver metastasis | No | 2,952 (85.7) | 1,251 (84.8) |
| Yes | 492 (14.3) | 225 (15.2) |
Data are presented as n (%). LUAD, lung adenocarcinoma; ADSQC, adenosquamous carcinoma; SQCC, squamous cell carcinoma; LCLC, large-cell lung carcinoma.