Table 1 Characteristics of patients and tumors included in the study
Characteristic | Training set (N = 1326) | Validation set (N = 838) | P value | ||
|---|---|---|---|---|---|
Age (years) | |||||
 Median (IQR) | 64 | (57, 70) | 65 | (58, 71) | .003* |
 <65 | 697 | (52.6) | 403 | (48.1) | .047** |
 ≥65 | 629 | (47.4) | 435 | (51.9) |  |
Gender | |||||
 Male | 801 | (60.4) | 511 | (61.0) | .826** |
 Female | 525 | (39.6) | 327 | (39.0) |  |
Smoking | |||||
 Ever smoker | 907 | (68.4) | 578 | (69.0) | .001** |
 Never smoker | 177 | (13.3) | 148 | (17.7) |  |
 Unknown | 242 | (18.3) | 112 | (13.4) |  |
Histology | |||||
 Adenocarcinoma | 880 | (66.4) | 420 | (50.1) | < .001** |
 Squamous cell carcinoma | 299 | (22.5) | 379 | (45.2) |  |
 Large cell carcinoma | 54 | (4.1) | 7 | (0.8) |  |
 Basaloid tumors | 31 | (2.3) | 32 | (3.8) |  |
 Large cell neuroendocrine carcinoma | 41 | (3.1) |  |  |  |
 Carcinoid Tumors | 21 | (1.6) |  |  |  |
Grade | |||||
 Well differentiated | 289 | (21.8) | 69 | (8.2) | < .001** |
 Moderately differentiated | 192 | (14.5) | 68 | (8.1) |  |
 Poorly differentiated | 85 | (6.4) | 33 | (3.9) |  |
 Unknown | 760 | (57.3) | 668 | (79.7) |  |
Tumor stage | |||||
 T1 | 456 | (34.4) | 319 | (38.1) | < .001** |
 T2 | 722 | (54.4) | 386 | (46.1) |  |
 T3 | 74 | (5.6) | 39 | (4.7) |  |
 Unknown | 74 | (5.6) | 94 | (11.2) |  |
Nodal status | |||||
 N0 | 908 | (68.5) | 583 | (69.6) | < .001** |
 N1 | 239 | (18.0) | 135 | (16.1) |  |
 N2 | 102 | (7.7) | 26 | (3.1) |  |
 Unknown | 77 | (5.8) | 94 | (11.2) |  |
TNM stage | |||||
 IA | 373 | (28.1) | 287 | (34.2) | < .001** |
 IB | 506 | (38.2) | 279 | (33.3) |  |
 II | 290 | (21.9) | 220 | (26.3) |  |
 IIIA | 157 | (11.8) | 52 | (6.2) |  |
EGFR | |||||
 Mutant type | 54 | (4.1) | 127 | (15.2) | < .001** |
 Wild type | 58 | (4.4) | 99 | (11.8) |  |
 Unknown | 1214 | (91.6) | 612 | (73.0) |  |
KRAS | |||||
 Mutant type | 15 | (1.1) | 30 | (3.6) | < .001** |
 Wild type | 67 | (5.1) | 263 | (31.4) |  |
 Unknown | 1244 | (93.8) | 545 | (65.0) |  |
ALK fusion | |||||
 Yes | 0 |  | 11 | (1.3) | NA |
 No | 0 |  | 215 | (25.7) |  |
 Unknown | 1326 | (100) | 612 | (73.0) |  |
TP53 | |||||
 Mutant type | 116 | (8.7) | 54 | (6.4) | < .001** |
 Wild type | 62 | (4.7) | 10 | (1.2) |  |
 Unknown | 1148 | (86.6) | 774 | (92.4) |  |
Median (range) follow-up (months) | 73.4 | (1, 256) | 61.9 | (1, 252) | < .001* |
Status | |||||
 Alive | 757 | (57.1) | 564 | (67.3) | < .001** |
 Dead | 569 | (42.9) | 274 | (32.7) |  |