Table 2.
Main characteristic distribution of data in training sets and test sets.
| Characteristic | Overall | Train | Test | p-value |
|---|---|---|---|---|
| N = 2197a | N = 1537a | N = 660a | ||
| Age (%) | 0.094 | |||
| > 66, ≤ 77 | 505 (23%) | 355 (23%) | 150 (23%) | |
| > 77 | 144 (6.6%) | 112 (7.3%) | 32 (4.8%) | |
| ≤ 66 | 1548 (70%) | 1070 (70%) | 478 (72%) | |
| Race (%) | 0.470 | |||
| American Indian/Alaska Native | 36 (1.6%) | 29 (1.9%) | 7 (1.1%) | |
| Asian or Pacific Islander | 478 (22%) | 323 (21%) | 155 (23%) | |
| Black | 228 (10%) | 157 (10%) | 71 (11%) | |
| White | 1455 (66%) | 1028 (67%) | 427 (65%) | |
| Marital status (%) | 0.298 | |||
| Married | 1319 (60%) | 924 (60%) | 395 (60%) | |
| Other | 878 (40%) | 613 (40%) | 265 (40%) | |
| Histological type (%) | 0.944 | |||
| 8170 | 2154 (98%) | 1507 (98%) | 647 (98%) | |
| 8171 | 2 (< 0.1%) | 2 (0.1%) | 0 (0.0%) | |
| 8172 | 3 (0.1%) | 3 (0.2%) | 0 (0.0%) | |
| 8173 | 3 (0.1%) | 1 (< 0.1%) | 2 (0.3%) | |
| 8174 | 34 (1.5%) | 23 (1.5%) | 11 (1.7%) | |
| 8175 | 1 (< 0.1%) | 1 (< 0.1%) | 0 (0.0%) | |
| Grade (%) | 0.719 | |||
| Moderately differentiated; Grade II | 1104 (50%) | 765 (50%) | 339 (51%) | |
| Poorly differentiated; Grade III | 402 (18%) | 288 (19%) | 114 (17%) | |
| Undifferentiated; anaplastic; Grade IV | 22 (1.0%) | 17 (1.1%) | 5 (0.8%) | |
| Well differentiated; Grade I | 669 (30%) | 467 (30%) | 202 (31%) | |
| T (%) | 0.713 | |||
| T1 | 1079 (49%) | 751 (49%) | 328 (50%) | |
| T2 | 677 (31%) | 484 (31%) | 193 (29%) | |
| T3a | 260 (12%) | 176 (11%) | 84 (13%) | |
| T3b | 124 (5.6%) | 84 (5.5%) | 40 (6.1%) | |
| T4 | 57 (2.6%) | 42 (2.7%) | 15 (2.3%) | |
| N (%) | 0.726 | |||
| N0 | 2114 (96%) | 1477 (96%) | 637 (97%) | |
| N1 | 83 (3.8%) | 60 (3.9%) | 23 (3.5%) | |
| M (%) | 0.370 | |||
| M0 | 2090 (95%) | 1452 (94%) | 638 (97%) | |
| M1 | 107 (4.9%) | 85 (5.5%) | 22 (3.3%) | |
| AFP (%) | 0.576 | |||
| Negative/normal; within normal limits | 753 (34%) | 533 (35%) | 220 (33%) | |
| Positive/elevated | 1444 (66%) | 1004 (65%) | 440 (67%) | |
| Tumor size (%) | 0.387 | |||
| > 62 mm | 568 (26%) | 406 (26%) | 162 (25%) | |
| ≤ 62 mm | 1629 (74%) | 1131 (74%) | 498 (75%) | |
| Surgery (%) | 0.843 | |||
| Lobectomy | 704 (32%) | 485 (32%) | 219 (33%) | |
| Local tumor destruction | 311 (14%) | 221 (14%) | 90 (14%) | |
| No | 753 (34%) | 526 (34%) | 227 (34%) | |
| Wedge or segmental resection | 429 (20%) | 305 (20%) | 124 (19%) | |
| Chemotherapy (%) | 0.525 | |||
| No/unknown | 1352 (62%) | 953 (62%) | 399 (60%) | |
| Yes | 845 (38%) | 584 (38%) | 261 (40%) | |
| Survival months (mean (SD)) | 45 (34) | 45 (34) | 46 (34) | 0.606 |
| Status (%) | 0.625 | |||
| Alive | 870 (40%) | 603 (39%) | 267 (40%) | |
| Dead | 1327 (60%) | 934 (61%) | 393 (60%) |
an (%); mean (SD).