Table 1 Characterizations of ESCC patients and normal controls used in study
|  | Discovery group (n = 162) | Validation group (n = 200) | ||
|---|---|---|---|---|
ESCC | NC | ESCC | NC | |
N | 62 | 62 | 100 | 100 |
Age | ||||
 Mean ± SD | 63.5 ± 8.3 | 62.5 ± 8.1 | 63.5 ± 8.1 | 62.3 ± 7.7 |
 Range | 44–88 | 50–83 | 42–84 | 43–83 |
Sex | ||||
 Male (%) | 43(69.35) | 43(69.35) | 66(66.00) | 66(66.00) |
 Female (%) | 19(30.65) | 19(30.65) | 34(34.00) | 34(34.00) |
Smoking | ||||
 Yes | 22(35.48) |  | 32(32.00) |  |
 None | 37(59.68) |  | 62(62.00) |  |
 Unknow | 3(4.84) |  | 6(6.00) |  |
Drinking | ||||
 Yes | 17(27.42) |  | 28(28.00) |  |
 None | 42(67.74) |  | 64(64.00) |  |
 Unknow | 3(4.84) |  | 8(8.00) |  |
Clinical stage | ||||
 I | 10(16.13) |  | 17(17.00) |  |
 II | 10(16.13) |  | 12(12.00) |  |
 III | 9(14.52) |  | 23(23.00) |  |
 IV | 8(12.90) |  | 8(8.00) |  |
 Unknow | 25(40.32) |  | 40(40.00) |  |
Differentiation | ||||
 High | 7(11.29) |  | 5(5.00) |  |
 Medium | 9(14.52) |  | 19(19.00) |  |
 Low | 9(14.52) |  | 21(21.00) |  |
 Unknow | 37(61.29) |  | 55(55.00) |  |
Tumor site | ||||
 Upper thorax | 14(22.58) |  | 9(9.00) |  |
 Middle thorax | 19(30.65) |  | 41(41.00) |  |
 Lower thorax | 15(24.19) |  | 21(21.00) |  |
 Unknow | 24(38.71) |  | 29(29.00) |  |
Family tumor history | ||||
 Yes | 3(4.84) |  | 10(10.00) |  |
 None | 55(88.71) |  | 83(83.00) |  |
 Unknow | 4(6.45) |  | 7(7.00) |  |
Lymphatic metastasis | ||||
 Positive | 17(27.42) |  | 28(28.00) |  |
 Negative | 24(38.71) |  | 36(36.00) |  |
 Unknow | 21(33.87) |  | 36(36.00) |  |
Distant metastasis | ||||
 Positive | 8(12.90) |  | 6(6.00) |  |
 Negative | 30(48.39) |  | 55(55.00) |  |
 Unknow | 24(38.71) |  | 39(39.00) |  |