Table 1. Characteristics of patients, cancer and surgery.
| Characteristics | No. of patients (%) |
|---|---|
| Demographics | |
| Men | 189 (73.3) |
| Age at operation (years), mean ± SD | 61±7 |
| Charlson comorbidity index, median (range) | 2 [0–6] |
| Follow-up time (months), median (range) | 26 [2–62] |
| Characteristics of cancer | |
| Location | |
| Upper esophagus | 34 (13.2) |
| Middle esophagus | 122 (47.3) |
| Lower esophagus | 102 (39.5) |
| Macroscopic type | |
| Flat type | 29 (11.2) |
| II | 29 (11.2) |
| Non-flat type | 193 (74.8) |
| III | 132 (51.2) |
| I | 61 (23.6) |
| Missing | 36 (14.0) |
| No. of synchronous esophageal carcinomas | |
| Multiple | 8 (3.1) |
| Solitary | 250 (96.9) |
| Tumor size (measured microscopically), median (range) | |
| Length (cm) | 1.8 (0.4–7.0) |
| Width (cm) | 1.0 (0.2–4.0) |
| Tumor volume (cm3) | 1.000 (0.016–36.750) |
| Degree of differentiation | |
| Well | 5 (1.9) |
| Moderate | 156 (60.5) |
| Poor | 97 (37.6) |
| Level of depth of invasion | |
| sm1 | 75 (29.1) |
| sm2 | 73 (28.3) |
| sm3 | 110 (42.6) |
| Lymphovascular invasion | |
| Positive | 18 (7.1) |
| Negative | 240 (92.9) |
| Harvested lymph nodes, median (range) | 10 [1–42] |
| pN category | |
| pN0 | 218 (84.5) |
| pN+ | 40 (15.6) |
| pN1 | 36 (14.0) |
| pN2 | 4 (1.6) |
| Distant metastasis | |
| M0 | 256 (99.2) |
| M1 | 2 (0.8) |
| Characteristics of surgery | |
| Surgical type | |
| Sweet procedure | 157 (60.9) |
| Ivor-Lewis procedure | 38 (14.7) |
| McKeown procedure | 12 (4.7) |
| Left cervical and left thoracic procedure | 3 (12.0) |
| Transhiatal procedure | 4 (1.6) |
| Minimally invasive esophagectomy | 44 (17.0) |
BMI, body mass index; SD, standard deviation; sm1, inner third submucosa; sm2, middle third submucosa; sm3, deep third submucosa; TNM, tumor, node, metastasis.