Table 3.
Characteristics of patients in the training and validation sets
| Variable | Training set (N = 5710) |
Validation set (N = 2832) |
|---|---|---|
| Median (IQR)/N (%) | Median (IQR)/N (%) | |
| Age, years | 66 (58-74) | 66 (58-74) |
| Race | ||
| White | 4688 (82.1) | 2326 (82.1) |
| Black | 602 (10.5) | 294 (10.4) |
| Other | 420 (7.3) | 212 (7.5) |
| Sex | ||
| Male | 2876 (50.4) | 1456 (51.4) |
| Female | 3227 (62.0) | 1376 (48.6) |
| Marital status | ||
| Married | 3554 (62.2) | 1764 (62.3) |
| Unmarried | 2002 (35.1) | 990 (35.0) |
| Unknown | 154 (2.7) | 78 (2.8) |
| Year of diagnosis | ||
| 2004-2006 | 1612 (28.2) | 825 (29.1) |
| 2007-2009 | 1989 (34.8) | 977 (34.5) |
| 2010-2012 | 2109 (36.9) | 1030 (36.4) |
| SEER region | ||
| Midwest | 901 (15.8) | 451 (15.9) |
| Northeast | 1110 (19.4) | 501 (17.7) |
| South | 1009 (17.7) | 477 (16.8) |
| West | 2690 (47.1) | 1403 (49.5) |
| Tumor site | ||
| Head | 4427 (77.5) | 2214 (78.2) |
| Body | 322 (5.6) | 156 (5.6) |
| Tail | 426 (7.5) | 222 (7.8) |
| Not specified | 535 (9.4) | 237 (8.4) |
| Tumor grade | ||
| I/II | 3277 (57.4) | 1586 (56.0) |
| III/IV | 1884 (33.0) | 972 (34.4) |
| Unknown | 549 (9.6) | 274 (9.7) |
| Tumor size | 31 (25-40) | 31 (25-40) |
| ≤2 cm (8th T1) | 951 (16.7) | 515 (18.2) |
| >2 cm and ≤4 cm (8th T2) | 3366 (58.9) | 1697 (59.9) |
| >4 cm (8th T3) | 1393 (24.4) | 620 (21.9) |
| 7th AJCC T stage | ||
| T1 | 339 (5.9) | 211 (7.5) |
| T2 | 833 (14.6) | 383 (13.5) |
| T3 | 4538 (79.5) | 2238 (79.0) |
| Positive node count | 1 (0-3) | 1 (0-3) |
| 0 (8th N0) | 2001 (35.0) | 1048 (37.0) |
| 1-3 (8th N1) | 1967 (34.4) | 902 (31.9) |
| ≥4 (8th N2) | 1742 (30.5) | 882 (31.1) |
| Examined node count | 13 (7-19) | 12 (7-19) |
IQR, interquartile range; SEER, Surveillance, Epidemiology, and End Results; AJCC, American Joint Committee on Cancer.