Table 1 Patient details and clinicopathological characteristics
Group | Training set (n = 513) | Internal validation set (n = 413) | External validation set 1 (n = 371) | External validation set 2 (n = 202) | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
ESCC (n = 388) | NC (n = 125) | ESCC (n = 312) | NC (n = 101) | ESCC (n = 237) | NC (n = 134) | ESCC (n = 101) | NC (n = 101) | |||||||||
No | % | No | % | No | % | No | % | No | % | No | % | No | % | No | % | |
Age, years | 59 ± 8 | 52 ± 9 | 58 ± 8 | 53 ± 11 | 59 ± 9 | 51 ± 10 | 61 ± 9 | 59 ± 9 | ||||||||
Sex | ||||||||||||||||
Male | 291 | 75.0 | 62 | 49.6 | 227 | 72.8 | 72 | 71.3 | 176 | 74.3 | 90 | 67.2 | 80 | 79.2 | 72 | 71.3 |
Female | 97 | 25.0 | 63 | 50.4 | 85 | 27.2 | 29 | 28.7 | 61 | 25.7 | 44 | 32.8 | 21 | 20.8 | 29 | 28.7 |
Smokers | 280 | 72.2 | 45 | 28.8 | 211 | 67.6 | 58 | 57.4 | 156 | 65.8 | Unknown | 47 | 55.3 | Unknown | ||
TNM stage | ||||||||||||||||
0 | 2 (2)§ | 0.5 | 5 | 1.6 | 2 | 0.8 | 6 | 5.9 | ||||||||
I | 29 (23)§ | 7.5 | 34 | 10.9 | 31 | 13.1 | 52 | 51.5 | ||||||||
II (IIA* + IIB*) | 96 (28 + 38)§ | 24.7 | 99 (33 + 66) | 31.7 | 114 (43 + 71) | 48.1 | 43 | 42.6 | ||||||||
III | 229 (135)§ | 59.0 | 168 | 53.8 | 90 | 38.0 | 0 | 0.0 | ||||||||
IV | 27 | 7.0 | 6 | 1.9 | 0 | 0.0 | 0 | 0.0 | ||||||||
Unknown | 5 | 1.3 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | ||||||||
Histological grade | ||||||||||||||||
High (grade 1) | 80 | 20.6 | 93 | 29.8 | 56 | 23.6 | 9 | 8.9 | ||||||||
Middle (grade 2) | 114 | 29.4 | 188 | 60.3 | 160 | 67.5 | 52 | 51.5 | ||||||||
Low (grade 3) | 23 | 6.0 | 31 | 9.9 | 21 | 8.9 | 29 | 28.7 | ||||||||
Unknown | 171 | 44.1 | 0 | 0.0 | 0 | 0.0 | 11 | 10.9 | ||||||||
Depth of tumor invasion | ||||||||||||||||
Tis | 2 (2)§ | 0.5 | 5 | 1.6 | 2 | 0.8 | 7 | 6.9 | ||||||||
T1 + T2 | 68 (50)§ | 17.5 | 74 | 23.7 | 58 | 24.5 | 64 | 63.4 | ||||||||
T3 + T4 | 310 (174)§ | 79.9 | 233 | 74.7 | 177 | 74.7 | 30 | 29.7 | ||||||||
Unknown | 8 | 2.1 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | ||||||||
Lymph node metastasis | ||||||||||||||||
Positive | 234 (125)§ | 60.3 | 153 | 49.0 | 103 | 43.5 | 0 | 0.0 | ||||||||
Negative | 146 (101)§ | 37.6 | 159 | 51.0 | 134 | 56.5 | 101 | 100 | ||||||||
Unknown | 8 | 2.1 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | ||||||||
Size of tumor | ||||||||||||||||
< 5 cm | 138 (104)§ | 35.6 | 141 | 45.2 | 185 | 78.1 | 89 | 88.1 | ||||||||
≥ 5 cm | 197 (112)§ | 50.8 | 171 | 54.8 | 52 | 21.9 | 9 | 8.9 | ||||||||
Unknown | 53 | 13.7 | 0 | 0.0 | 0 | 0.0 | 3 | 3.0 | ||||||||
Site of tumor | ||||||||||||||||
Cervical esophagus | 8 | 2.1 | 2 | 0.6 | 0 | 0.0 | 0 | 0.0 | ||||||||
Upper thorax | 59 (28)§ | 15.2 | 43 | 13.8 | 18 | 7.6 | 7 | 6.9 | ||||||||
Middle thorax | 270 (164)§ | 69.6 | 217 | 69.6 | 155 | 65.4 | 59 | 58.4 | ||||||||
Lower thorax | 47 (34)§ | 12.1 | 50 | 16.0 | 62 | 26.2 | 35 | 34.7 | ||||||||
Unknown | 4 | 1.0 | 0 | 0.0 | 2 | 0.8 | 0 | 0.0 | ||||||||