Characteristic | Total (n = 25,005) | Training cohort (n = 13,551) | External validation cohort (n = 11,454) | P value | |||
---|---|---|---|---|---|---|---|
N | % | N | % | N | % | ||
Age at diagnosis (year) |  |  |  |  |  |  | < 0.001 |
  < 50 | 1288 | 5.2 | 806 | 5.9 | 482 | 4.2 |  |
 50–59 | 4898 | 19.6 | 2967 | 21.9 | 1931 | 16.9 |  |
 60–69 | 8830 | 35.3 | 4829 | 35.6 | 4001 | 34.9 |  |
 70–79 | 7683 | 30.7 | 3894 | 28.7 | 3789 | 33.1 |  |
  ≥ 80 | 2306 | 9.2 | 1055 | 7.8 | 1251 | 10.9 |  |
Sex | Â | Â | Â | Â | Â | Â | 0.021 |
 Male | 10,680 | 42.7 | 5878 | 43.4 | 4802 | 41.9 |  |
 Female | 14,325 | 57.3 | 7673 | 56.6 | 6652 | 58.1 |  |
Race |  |  |  |  |  |  | < 0.001 |
 White | 20,416 | 81.6 | 11,639 | 85.9 | 8777 | 76.6 |  |
 Black | 2287 | 9.1 | 1638 | 12.1 | 649 | 5.7 |  |
 Other | 2302 | 9.2 | 274 | 2.0 | 2028 | 17.7 |  |
Marital status at diagnosis |  |  |  |  |  |  | < 0.001 |
 Single | 2942 | 11.8 | 1479 | 10.9 | 1463 | 12.8 |  |
 Married | 14,917 | 59.7 | 8095 | 59.7 | 6822 | 59.6 |  |
 Other | 7146 | 28.6 | 3977 | 29.3 | 3169 | 27.7 |  |
Laterality | Â | Â | Â | Â | Â | Â | 0.026 |
 Right | 15,015 | 60.0 | 8223 | 60.7 | 6792 | 59.3 |  |
 Left | 9990 | 40.0 | 5328 | 39.3 | 4662 | 40.7 |  |
Site | Â | Â | Â | Â | Â | Â | 0.006 |
 Main bronchus | 40 | 0.2 | 21 | 0.2 | 19 | 0.2 |  |
 Upper lobe | 15,359 | 61.4 | 8454 | 62.4 | 6905 | 60.3 |  |
 Middle lobe | 1317 | 5.3 | 674 | 5.0 | 643 | 5.6 |  |
 Lower lobe | 7983 | 31.9 | 4231 | 31.2 | 3752 | 32.8 |  |
 Over lapping lesion of lung | 306 | 1.2 | 171 | 1.3 | 135 | 1.2 |  |
Differentiation |  |  |  |  |  |  | < 0.001 |
 I (Well differentiated) | 4568 | 18.3 | 2298 | 17.0 | 2270 | 19.8 |  |
 II (Medium differentiated) | 12,401 | 49.6 | 6655 | 49.1 | 5746 | 50.2 |  |
 III (Poorly differentiated) | 7851 | 31.4 | 4506 | 33.3 | 3345 | 29.2 |  |
 IV (Undifferentiated) | 185 | 0.7 | 92 | 0.7 | 93 | 0.8 |  |
T classification | Â | Â | Â | Â | Â | Â | 0.028 |
 T1 | 11,856 | 47.4 | 6529 | 48.2 | 5327 | 46.5 |  |
 T2 | 8832 | 35.3 | 4701 | 34.7 | 4131 | 36.1 |  |
 T3 | 2976 | 11.9 | 1580 | 11.7 | 1396 | 12.2 |  |
 T4 | 1341 | 5.4 | 741 | 5.5 | 600 | 5.2 |  |
N classification | Â | Â | Â | Â | Â | Â | 0.502 |
 N0 | 18,541 | 74.1 | 10,080 | 74.4 | 8461 | 73.9 |  |
 N1 | 3366 | 13.5 | 1774 | 13.1 | 1592 | 13.9 |  |
 N2 | 3098 | 12.4 | 1697 | 12.5 | 1401 | 12.2 |  |
Type of surgery |  |  |  |  |  |  | < 0.001 |
 Sublobectomy | 2831 | 11.3 | 1707 | 12.6 | 1124 | 9.8 |  |
 Lobectomy | 21,499 | 86.0 | 11,441 | 84.4 | 10,058 | 87.8 |  |
 Pneumonectomy | 675 | 2.7 | 403 | 3.0 | 272 | 2.4 |  |
Radiotherapy |  |  |  |  |  |  | < 0.001 |
 No | 22,786 | 91.1 | 12,262 | 90.5 | 10,524 | 91.9 |  |
 Yes | 2219 | 8.9 | 1289 | 9.5 | 930 | 8.1 |  |
Chemotherapy |  |  |  |  |  |  | < 0.001 |
 No | 18,282 | 73.1 | 9737 | 71.9 | 8545 | 74.6 |  |
 Yes | 6723 | 26.9 | 3814 | 28.1 | 2909 | 25.4 |  |
NDLN | Â | Â | Â | Â | Â | Â | 0.277 |
 NDLN1 (1–10) | 15,958 | 63.8 | 8717 | 64.3 | 7241 | 63.2 |  |
 NDLN2 (11–19) | 6399 | 25.6 | 3345 | 24.7 | 3054 | 26.7 |  |
 NDLN3 (≥20) | 2648 | 10.6 | 1489 | 11.0 | 1159 | 10.1 |  |
NPLN | Â | Â | Â | Â | Â | Â | 0.301 |
 NPLN0 (0) | 18,726 | 74.9 | 10,186 | 75.2 | 8540 | 74.6 |  |
 NPLN1 (1–6) | 5656 | 22.6 | 3022 | 22.3 | 2634 | 23.0 |  |
 NPLN2 (≥7) | 623 | 2.5 | 343 | 2.5 | 280 | 2.4 |  |
LODDS | Â | Â | Â | Â | Â | Â | 0.371 |
 LODDS1 (<−0.94) | 15,712 | 62.8 | 8427 | 62.2 | 7285 | 63.6 |  |
 LODDS2 (≥ − 0.94, <−0.41) | 6211 | 24.8 | 3451 | 25.5 | 2760 | 24.1 |  |
 LODDS3 (≥ − 0.41) | 3082 | 12.3 | 1673 | 12.3 | 1409 | 12.3 |  |
LNR | Â | Â | Â | Â | Â | Â | 0.045 |
 LNR0 (0) | 18,726 | 74.9 | 10,186 | 75.2 | 8540 | 74.6 |  |
 LNR1 (> 0, < 0.55) | 5120 | 20.5 | 2716 | 20.0 | 2404 | 21.0 |  |
 LNR2 (≥0.55, ≤1) | 1159 | 4.6 | 649 | 4.8 | 510 | 4.5 |  |