Table 1.
Demographic and clinicopathological characteristics of the training and validation cohorts.
| Variables | Entire cohort (n=2285) (N, %) | Training cohort (n=1601) (N, %) | Validation cohort (n=684) (N, %) |
|---|---|---|---|
| Age (years) | |||
| <65 | 622 (27.2) | 436 (27.2) | 186 (27.1) |
| >= 65 | 1663 (72.8) | 1165 (72.8) | 498 (72.9) |
| Sex | |||
| Female | 877 (38.4) | 616 (38.4) | 261 (38.1) |
| Male | 1408 (61.6) | 985 (61.6) | 423 (61.9) |
| Race | |||
| White | 1862 (81.5) | 1303 (81.4) | 559 (81.7) |
| Black | 252 (11.0) | 175 (10.9) | 77 (11.2) |
| Other | 171 (7.5) | 123 (7.7) | 48 (7.1) |
| Histology of lung cancer | |||
| Adenocarcinoma | 863 (37.8) | 618 (38.6) | 245 (35.8) |
| Squamous cell carcinomas | 510 (22.3) | 366 (22.9) | 144 (21.1) |
| Small cell cancer | 213 (9.3) | 142 (8.8) | 71 (10.4) |
| Others | 699 (30.6) | 475 (29.7) | 224 (32.7) |
| Location of FPC | |||
| Prostate | 486 (21.3) | 331 (20.6) | 155 (22.6) |
| Female Breast | 308 (13.5) | 210 (13.1) | 98 (14.4) |
| Urinary Bladder | 238 (10.4) | 174 (10.9) | 64 (9.3) |
| Others | 1253 (54.8) | 886 (55.4) | 367 (53.7) |
| Stage of lung cancer | |||
| Stage I | 843 (36.9) | 602 (37.6) | 241 (35.2) |
| Stage II | 217 (9.5) | 159 (9.9) | 58 (8.5) |
| Stage III | 414 (18.1) | 298 (18.7) | 116 (16.9) |
| Stage IV | 811 (35.5) | 542 (33.8) | 269 (39.4) |
| Surgery | |||
| No | 1511 (66.1) | 1048 (65.4) | 463 (67.6) |
| Yes | 774 (33.9) | 553 (34.6) | 221 (32.4) |
| Interval (months) | |||
| <24 | 1391 (60.9) | 986 (61.5) | 405 (59.2) |
| 24 - 47 | 695 (30.4) | 479 (30.0) | 216 (31.5) |
| 48 - 72 | 199 8.7) | 136 (8.5) | 63 (9.3) |
| Year of diagnosis | |||
| 2010 | 81 (3.5) | 59 (3.6) | 22 (3.3) |
| 2011 | 228 (10.0) | 166 (10.4) | 64 (9.3) |
| 2012 | 344 (15.1) | 239 (14.9) | 105 (15.4) |
| 2013 | 436 (19.1) | 301 (18.8) | 135 (19.7) |
| 2014 | 569 (24.9) | 394 (24.7) | 175 (25.6) |
| 2015 | 625 (27.4) | 442 (27.6) | 183 (26.7) |