Table 1. Baseline characteristics.
| Patient characteristic | No. (%) |
|---|---|
| Sex | |
| Male | 614 (89.2%) |
| Female | 74 (10.8%) |
| Age, y | |
| <58 | 345 (50.1%) |
| ≥58 | 343 (49.9%) |
| Smoking status | |
| Non-smoker | 163 (23.7%) |
| Smoker | 526 (76.5%) |
| Drinking status | |
| Non-drinker | 223 (32.4%) |
| Drinker | 465 (67.6%) |
| Tumor size (cm) | |
| ≤2 cm | 348 (50.6%) |
| >2 cm | 340 (49.4%) |
| Pathologic T stage | |
| T1 or T2 | 105 (15.3%) |
| T3 or T4 | 583 (84.7%) |
| Tumor location | |
| Upper | 13 (1.9%) |
| Middle | 282 (41.0%) |
| Lower | 393 (57.1%) |
| Tumor differentiation | |
| Well | 75 (10.9%) |
| Intermediate | 475 (69.1%) |
| Poor or undifferentiated | 137 (19.9%) |
| Lymph node metastasis (2009) | |
| N1 | 328 (47.7%) |
| N2 | 254 (36.9%) |
| N3 | 106 (15.4%) |
| Involved LNR | |
| >0.15 | 244 (35.5%) |
| ≤0.15 | 444 (64.5%) |
| Clinical stage | |
| IIB | 73 (10.6%) |
| IIIA | 270 (39.2%) |
| IIIB | 233 (33.9%) |
| IIIC | 112 (16.3%) |
| Venous/lymphatic invasion | |
| No | 482 (70.1%) |
| Yes | 206 (29.9%) |
| Perineural invasion | |
| No | 468 (68.0%) |
| Yes | 220 (32.0%) |
| No. of LN regions involved | |
| One region | 339 (51.8%) |
| Two regions | 246 (37.6%) |
| Three or four regions | 69 (10.6%) |
| Adjuvant radiotherapy or chemotherapy | |
| No | 452 (65.7%) |
| Yes | 236 (34.3%) |
Abbreviations: LN = lymph node; LNR = lymph node ratio