Table 1. Clinicopathologic characteristics of patients.
| Clinicopathologic features | Number (%) |
| Gender | |
| Female | 140 (31.7) |
| Male | 302 (68.3) |
| Age (years) | |
| ≤50 | 113 (25.6) |
| >50 | 329 (74.4) |
| Tumor size (cm) | |
| <6 | 390 (88.2) |
| ≥6 | 52 (11.8) |
| Tumor location | |
| Upper third | 101 (22.9) |
| Middle third | 65 (14.7) |
| Lower third | 253 (57.2) |
| ≥Two thirds | 23 (5.2) |
| Histological type | |
| Well-differentiated | 13 (2.9) |
| Moderately-differentiated | 129 (29.2) |
| Poorly-differentiated | 281 (63.6) |
| Undifferentiated | 19 (4.3) |
| Depth of invasion in muscularis propria | |
| Shallow muscular layer | 263 (59.5) |
| Deep muscular layer | 179 (40.5) |
| Vascular tumor emboli | |
| Yes | 105 (23.8) |
| No | 337 (76.2) |
| Nervous invasion | |
| Yes | 67 (15.2) |
| No | 375 (84.8) |
| Lymph node metastasis | |
| Yes | 203 (45.9) |
| No | 239 (54.1) |
| Pathological stage | |
| IB (T2N0M0) | 239 (54.1) |
| IIA (T2N1M0) | 91 (20.6) |
| IIB (T2N2M0) | 65 (14.7) |
| IIIA (T2N3M0) | 47 (10.6) |