Table 1. Characteristics of the study population.
| Variable | Total (n=447) | Training Set (n=224) | Testing Set (n=223) | P |
|---|---|---|---|---|
| Age(yeras) | 0.104* | |||
| < 65 | 154 (34.5%) | 69 (30.8%) | 85 (38.1%) | |
| ≥ 65 | 293 (65.5%) | 155 (69.2%) | 138 (61.9%) | |
| Sex | 0.569 | |||
| Male | 332 (74.4%) | 169 (75.4%) | 163 (73.1%) | |
| Female | 115 (25.7%) | 55 (24.6%) | 60 (26.9%) | |
| Vital status | 0672† | |||
| Alive | 263 (58.8%) | 134 (59.8%) | 129 (57.8%) | |
| Dead | 184 (41.2%) | 90 (40.2%) | 94 (42.2%) | |
| Stage | 0.366 | |||
| I | 211 (47.2%) | 113 (50.4%) | 98 (43.9%) | |
| II | 153 (34.2%) | 75(33.5%) | 78 (35.0%) | |
| III | 78 (17.4) | 33 (14.6%) | 45 (20.2%) | |
| IV | 5 (1.1%) | 3 (1.3%) | 2 (0.9%) | |
| T stage | 0.896 | |||
| T1 | 179 (40.0%) | 87 (38.8%) | 92 (41.3%) | |
| T2 | 203 (45.5%) | 103 (46.0%) | 100 (44.8%) | |
| T3 | 55 (12.3%) | 28 (12.5%) | 27 (12.1%) | |
| T4 | 10 (2.2%) | 6 (2.7%) | 4 (1.8%) | |
| N stage | 0.903 | |||
| N0 | 279 (62.4%) | 142 (63.4%) | 137 (61.4%) | |
| N1 | 130 (29.1%) | 63 (28.1%) | 67 (30.0%) | |
| N2 | 35 (7.8%) | 18 (8.0%) | 17 (7.6%) | |
| N3 | 3 (0.7%) | 1 (0.4%) | 2 (0.9%) | |
| M stage | 1.000 | |||
| M0 | 442 (98.9%) | 221 (98.7%) | 221 (99.1%) | |
| M1 | 5 (1.1%) | 3 (1.3%) | 2 (0.9%) | |
| Smoke status | 0.337 | |||
| Smoker | 293 (65.5%) | 142 (63.4%) | 151 (67.7%) | |
| Nonsmoker | 154 (34.5%) | 82 (36.6%) | 72 (32.3) | |
| Adjuvant treatment | 0.279 | |||
| None | 296 (66.2%) | 154 (68.8%) | 142 (63.7%) | |
| Chemotherapy | 94 (21.0%) | 44 (19.6%) | 50 (22.4) | |
| Radiotherapy | 16 (3.6%) | 10 (4.5%) | 6 (2.7%) | |
| Chemoradiotherapy | 41 (9.2%) | 16 (7.1%) | 25 (11.2%) |