Table 1.
Patients' demographics and clinicopathological characteristics
| Characteristics | Total cohort | Training cohort | Validation cohort | P value |
|---|---|---|---|---|
| 32,474 (100%) | 22,732 (70.0%) | 9742 (30.0%) | ||
| Age | 0.486 | |||
| 60–69 | 11,325 (34.9%) | 7935 (34.9%) | 3390 (34.8%) | |
| 70–79 | 14,214 (43.8%) | 9982 (43.9%) | 4232 (43.4%) | |
| ≥ 80 | 6935 (21.4%) | 4815 (21.2%) | 2120 (21.8%) | |
| Sex | 0.456 | |||
| Male | 19,835 (61.1%) | 13,848 (60.9%) | 5987 (61.5%) | |
| Female | 12,639 (38.9%) | 8884 (39.1%) | 3755 (38.5%) | |
| Race | 0.059 | |||
| White | 27,573 (84.9%) | 19,333 (85.1%) | 8240 (84.6%) | |
| Black | 3396 (10.5%) | 2366 (10.4%) | 1030 (10.6%) | |
| Asian or Pacific Islander | 1320 (4.1%) | 892 (3.9%) | 428 (4.4%) | |
| American Indian/Alaska Native | 185 (0.6%) | 141 (0.6%) | 44 (0.5%) | |
| Marital status | 0.674 | |||
| Married | 16,673 (51.3%) | 11,673 (51.4%) | 5000 (51.3%) | |
| Unmarried | 14,525 (44.7%) | 10,152 (44.7%) | 4373 (44.9%) | |
| Unknown | 1276 (3.9%) | 907 (4.0%) | 369 (3.8%) | |
| Tumor site | 0.665 | |||
| Main bronchus | 1353 (4.2%) | 934 (4.1%) | 419 (4.3%) | |
| Upper lobe, lung | 17,829 (54.9%) | 12,498 (55.0%) | 5331 (54.7%) | |
| Middle lobe, lung | 1254 (3.9%) | 877 (3.9%) | 377 (3.9%) | |
| Lower lobe, lung | 10,212 (31.5%) | 7154 (31.5%) | 3058 (31.4%) | |
| Overlapping lesion of lung | 358 (1.1%) | 237 (1.0%) | 121 (1.2%) | |
| Lung, NOS | 1468 (4.5%) | 1032 (4.5%) | 436 (4.5%) | |
| Laterality | 0.926 | |||
| One side | 32,203 (99.2%) | 22,543 (99.2%) | 9660 (99.2%) | |
| Bilateral | 271 (0.8%) | 189 (0.8%) | 82 (0.8%) | |
| Grade | 0.650 | |||
| I | 1023 (3.2%) | 726 (3.2%) | 297 (3.1%) | |
| II | 13,902 (42.8%) | 9704 (42.7%) | 4198 (43.1%) | |
| III | 17,252 (53.1%) | 12,101 (53.2%) | 5151 (52.9%) | |
| IV | 297 (0.9%) | 201 (0.9%) | 96 (1.0%) | |
| AJCC stage | 0.679 | |||
| I | 10,216 (31.5%) | 7193 (31.6%) | 3023 (31.0%) | |
| II | 4970 (15.3%) | 3480 (15.3%) | 1490 (15.3%) | |
| III | 8313 (25.6%) | 5812 (25.6%) | 2501 (25.7%) | |
| IV | 8975 (27.6%) | 6247 (27.5%) | 2728 (28.0%) | |
| Tumor size | 0.302 | |||
| ≤ 30 | 10,783 (33.2%) | 7569 (33.3%) | 3214 (33.0%) | |
| 31–50 | 8669 (26.7%) | 6117 (26.9%) | 2552 (26.2%) | |
| 51–70 | 5770 (17.8%) | 4001 (17.6%) | 1769 (18.2%) | |
| > 70 | 4650 (14.3%) | 3258 (14.3%) | 1392 (14.3%) | |
| Unknown | 2602 (8.0%) | 1787 (7.9%) | 815 (8.4%) | |
| Bone metastasis | 0.148 | |||
| Yes | 2475 (7.6%) | 1715 (7.5%) | 760 (7.8%) | |
| No | 29,558 (91.0%) | 20,691 (91.0%) | 8867 (91.0%) | |
| Unknown | 441 (1.4%) | 326 (1.4%) | 115 (1.2%) | |
| Brain metastasis | 0.433 | |||
| Yes | 1255 (3.9%) | 863 (3.8%) | 392 (4.0%) | |
| No | 30,764 (94.7%) | 21,542 (94.8%) | 9222 (94.7%) | |
| Unknown | 455 (1.4%) | 327 (1.4%) | 128 (1.3%) | |
| Liver metastasis | 0.199 | |||
| Yes | 1325 (4.1%) | 909 (4.0%) | 416 (4.3%) | |
| No | 30,707 (94.5%) | 21,500 (94.6%) | 9207 (94.5%) | |
| Unknown | 442 (1.4%) | 323 (1.4%) | 119 (1.2%) | |
| Lung metastasis | 0.573 | |||
| Yes | 2993 (9.2%) | 2101 (9.2%) | 892 (9.2%) | |
| No | 28,973 (89.2%) | 20,286 (89.2%) | 8687 (89.2%) | |
| Unknown | 508 (1.6%) | 345 (1.5%) | 163 (1.7%) | |
| Surgery | 0.492 | |||
| Yes | 12,009 (37.0%) | 8379 (36.9%) | 3630 (37.3%) | |
| No | 20,465 (63.0%) | 14,353 (63.1%) | 6112 (62.7%) | |
| Radiation | 0.443 | |||
| Yes | 13,393 (41.2%) | 9344 (41.1%) | 4049 (41.6%) | |
| No | 19,081 (58.8%) | 13,388 (58.9%) | 5693 (58.4%) | |
| Chemotherapy | 0.865 | |||
| Yes | 11,796 (36.3%) | 8264 (36.4%) | 3532 (36.3%) | |
| No | 20,678 (63.7%) | 14,468 (63.6%) | 6210 (63.7%) | |
| Insurance | 0.377 | |||
| Yes | 28,421 (87.5%) | 19,919 (87.6%) | 8502 (87.3%) | |
| No | 4053 (12.9%) | 2813 (12.4%) | 1240 (12.7%) | |
| Median follow-up time (Months, 25th–75th percentile) | 10 (3–24) | 10 (3–25) | 10 (3–24) | 0.879 |
AJCC The American Joint Committee for Cancer