Table 1. Characteristics of patients.
| Characteristic | No. of patients (%) |
|---|---|
| Sex | |
| Male | 393(78.9) |
| Female | 105(21.1) |
| Age, y | |
| Median | 59 |
| Range | 38–81 |
| ABO blood group | |
| A | 152(30.5) |
| B | 136(27.3) |
| O | 110(22.1) |
| AB | 64(12.9) |
| Unkown | 36(7.2) |
| Length of smoking time (year) | |
| None | 157(31.5) |
| 1–10 | 35(7) |
| 11–20 | 76(15.3) |
| 21–30 | 130(26.1) |
| 30– | 100(20.1) |
| Length of alcohol drinking time (year) | |
| None | 211(42.4) |
| 1–10 | 19(3.8) |
| 11–20 | 101(20.3) |
| 21–30 | 100(20.1) |
| 30– | 67(13.5) |
| Family history in first degree relatives with any cancer | |
| None | 423(84.9) |
| Yes | 75(15.1) |
| Types of esophageal resection | |
| Ivor-Lewis esophagectomy | 143(28.7) |
| Three-field esophagectomy | 47(9.4) |
| Minimally invasive esophagectomy | 17(3.4) |
| Left thoracic | 275(55.2) |
| Unkown | 16(3.2) |
| Tumor length (cm) | |
| ≤3 | 185(37.1) |
| >3 | 313(62.9) |
| Tumor classification | |
| Tis | 7(1.4) |
| T1 | 47(9.4) |
| T2 | 105(21.1) |
| T3 | 314(63.1) |
| T4 | 21(4.2) |
| Unknown | 4(0.8) |
| Lymph node classification | |
| N0 | 294(59) |
| N1 | 102(20.5) |
| N2 | 76(15.3) |
| N3 | 22(4.4) |
| Unknown | 4(0.8) |
| Grade | |
| Well differentiated | 16(3.2) |
| Moderately differentiated | 396(79.5) |
| Poorly differentiated | 66(13.3) |
| Undifferentiated | 1(0.2) |
| Unknown | 19(3.8) |