Demographic characteristics of the patients
| Characteristic | Patients (n=2510) | P value | Patients (n=2510) | P value | Patients (n=2510) | |||||
| Non-Smoker (n=1340) | Smoker (n=1170) | Non-Drinker (n=1841) | Drinker (n=669) | None (n=1286) | Smoker-Only (n=555) | Drinker-Only (n=54) | Both (n=615) | |||
| KPS | <0.001 | <0.001 | ||||||||
| ≥90 | 973 (72.6%) | 446 (38.1%) | 1161 (63.1%) | 258 (38.6%) | 953 (74.1%) | 208 (37.5%) | 20 (37.0%) | 238 (38.7%) | ||
| ≤80 | 367 (27.4%) | 724 (61.9%) | 680 (36.9%) | 411 (61.4%) | 333 (25.9%) | 347 (62.5%) | 34 (63.0%) | 377 (61.3%) | ||
| Sex | <0.001 | <0.001 | ||||||||
| Male | 898 (67.0%) | 1162 (99.3%) | 1399 (76.0%) | 661 (98.8%) | 849 (66.0%) | 550 (99.1%) | 49 (90.7%) | 612 (99.5%) | ||
| Female | 442 (33.0%) | 8 (0.7%) | 442 (24.0%) | 8 (1.2%) | 437 (34.0%) | 5 (0.9%) | 5 (9.3%) | 3 (0.5%) | ||
| Age, years | 63 (35–90) | 61 (34–85) | <0.001 | 62 (34–90) | 62 (39–85) | 0.402 | 63 (35–90) | 60 (34–84) | 64 (45–81) | 62 (39–85) |
| Tumour grade | 0.005 | 0.088 | ||||||||
| Well G1 | 250 (18.7%) | 205 (17.5%) | 334 (18.1%) | 121 (18.1%) | 240 (18.7%) | 94 (16.9%) | 10 (18.5%) | 111 (18.0%) | ||
| Moderate G2 | 519 (38.7%) | 527 (45.0%) | 745 (40.5%) | 301 (45.0%) | 498 (38.7%) | 247 (44.5%) | 21 (38.9%) | 280 (45.5%) | ||
| Poor or undifferentiated G3 | 571 (42.6%) | 438 (37.4%) | 762 (41.4%) | 247 (36.9%) | 548 (42.6%) | 214 (38.6%) | 23 (42.6%) | 224 (36.4%) | ||
| Lymphovascular invasion | 0.036 | 0.055 | ||||||||
| Yes | 216 (16.1%) | 226 (19.3%) | 308 (16.7%) | 134 (20.0%) | 203 (15.8%) | 105 (18.9%) | 13 (24.1%) | 121 (19.7%) | ||
| No | 1124 (83.9%) | 944 (80.7%) | 1533 (83.3%) | 535 (80.0%) | 1083 (84.2%) | 450 (81.1%) | 41 (75.9%) | 494 (80.3%) | ||
| Nerve invasion | 0.129 | <0.001 | ||||||||
| Yes | 245 (18.3%) | 242 (20.7%) | 326 (17.7%) | 161 (24.1%) | 230 (17.9%) | 96 (17.3%) | 15 (27.8%) | 146 (23.7%) | ||
| No | 1095 (81.7%) | 928 (79.3%) | 1515 (82.3%) | 508 (75.9%) | 1056 (82.1%) | 459 (82.7%) | 39 (72.2%) | 469 (76.3%) | ||
| Tumour location | <0.001 | <0.001 | ||||||||
| Upper | 390 (29.1%) | 197 (16.8%) | 479 (26.0%) | 108 (16.1%) | 377 (29.3%) | 102 (18.4%) | 13 (24.1%) | 95 (15.4%) | ||
| Middle | 722 (53.9%) | 645 (55.1%) | 988 (53.7%) | 379 (56.7%) | 688 (53.5%) | 300 (54.1%) | 34 (63.0%) | 345 (56.1%) | ||
| Lower | 228 (17.0%) | 328 (28.0%) | 374 (20.3%) | 182 (27.2%) | 221 (17.2%) | 153 (27.6%) | 7 (13.0%) | 175 (28.5%) | ||
| Pathological T stage | 0.002 | 0.009 | ||||||||
| T1 | 126 (9.4%) | 76 (6.5%) | 147 (8.0%) | 55 (8.2%) | 123 (9.6%) | 24 (4.3%) | 3 (5.6%) | 52 (8.5%) | ||
| T2 | 287 (21.4%) | 222 (19.0%) | 374 (20.3%) | 135 (20.2%) | 273 (21.2%) | 101 (18.2%) | 14 (25.9%) | 121 (19.7%) | ||
| T3 | 802 (59.9%) | 782 (66.8%) | 1183 (64.3%) | 401 (59.9%) | 776 (60.3%) | 407 (73.3%) | 26 (48.1%) | 375 (61.0%) | ||
| T4 | 125 (9.3%) | 90 (7.7%) | 137 (7.4%) | 78 (11.7%) | 114 (8.9%) | 23 (4.1%) | 11 (20.4%) | 67 (10.9%) | ||
| Pathological N stage | 0.018 | 0.584 | ||||||||
| N0 | 609 (45.4%) | 475 (40.6%) | 805 (43.7%) | 279 (41.7%) | 587 (45.6%) | 218 (39.3%) | 22 (40.7%) | 257 (41.8%) | ||
| N1 | 405 (30.2%) | 356 (30.4%) | 555 (30.1%) | 206 (30.8%) | 387 (30.1%) | 168 (30.3%) | 18 (33.3%) | 188 (30.6%) | ||
| N2 | 228 (17.0%) | 222 (10.9%) | 320 (17.4%) | 130 (19.4%) | 216 (16.8%) | 104 (18.7%) | 12 (22.2%) | 118 (19.2%) | ||
| N3 | 98 (7.3%) | 117 (10.0%) | 161 (8.7%) | 54 (8.1%) | 96 (7.5%) | 65 (11.7%) | 2 (3.7%) | 52 (8.5%) | ||
| TNM stage | 0.051 | 0.824 | ||||||||
| I | 125 (9.3%) | 77 (6.6%) | 148 (8.0%) | 54 (8.1%) | 121 (9.4%) | 27 (4.9%) | 4 (7.4%) | 50 (8.1%) | ||
| II | 468 (34.9%) | 397 (33.9%) | 644 (35.0%) | 221 (33.0%) | 450 (35.0%) | 194 (35.0%) | 18 (33.3%) | 203 (33.0%) | ||
| III | 600 (44.8%) | 552 (47.2%) | 839 (45.6%) | 313 (46.8%) | 577 (44.9%) | 262 (47.2%) | 23 (42.6%) | 290 (47.2%0 | ||
| IV | 147 (11.0%) | 144 (12.3%) | 210 (11.4%) | 81 (12.1%) | 138 (10.7%) | 72 (13.0%) | 9 (16.7%) | 72 (11.7%) | ||
| Thoracic surgery | <0.001 | <0.001 | ||||||||
| MIE | 702 (52.4%) | 497 (42.5%) | 803 (43.6%) | 396 (59.2%) | 667 (51.9%) | 136 (24.5%) | 35 (64.8%) | 361 (58.7%) | ||
| OO | 638 (47.6%) | 673 (57.5%) | 1038 (56.4%) | 273 (40.8%) | 619 (48.1%) | 419 (75.5%) | 19 (35.2%) | 254 (41.3%) | ||
| Abdominal surgery | <0.001 | <0.001 | ||||||||
| MIE | 559 (417%) | 405 (34.6%) | 629 (34.2%) | 335 (50.1%) | 531 (41.3%) | 98 (17.7%) | 28 (51.9%) | 307 (49.9%) | ||
| OO | 780 (58.2%) | 762 (65.1%) | 1209 (65.7%) | 333 (49.8%) | 754 (58.6%) | 455 (82.0%) | 26 (48.1%) | 307 (49.9%) | ||
| NO | 1 (0.1%) | 3 (0.3%) | 3 (0.2%) | 1 (0.1%) | 1 (0.1%) | 2 (0.4%) | 0 (0.0%) | 1 (0.2%) | ||
| Surgical approach | <0.001 | <0.001 | ||||||||
| McKeown | 1030 (76.9%) | 749 (64.0%) | 1254 (68.1%) | 525 (78.5%) | 987 (76.7%) | 267 (48.1%) | 43 (79.6%) | 482 (78.4%) | ||
| Iovr-Lewis | 292 (21.8%) | 399 (34.1%) | 560 (30.4%) | 131 (19.6%) | 281 (21.9%) | 279 (50.3%) | 11 (20.4%) | 120 (19.5%) | ||
| Sweet | 1 (0.1%) | 3 (0.3%) | 3 (0.2%) | 1 (0.1%) | 1 (0.1%) | 2 (0.4%) | 0 (0.0%) | 1 (0.2%) | ||
| Left thoracotomy and laparotomy | 17 (1.3%) | 19 (1.6%) | 24 (1.3%) | 12 (1.8%) | 17 (1.3%) | 7 (1.3%) | 0 (0.0%) | 12 (2.0%) | ||
| Clinical treatment modality | <0.001 | 0.052 | ||||||||
| Preoperative CT or RT/CRT plus surgery | 28 (2.1%) | 18 (1.5%) | 34 (1.8%) | 12 (1.8%) | 27 (2.1%) | 7 (1.3%) | 1 (1.9%) | 11 (1.8%) | ||
| Surgery alone | 817 (61.0%) | 452 (38.6%) | 904 (49.1%) | 365 (54.6%) | 784 (61.0%) | 120 (21.6%) | 33 (61.1%) | 332 (54.0%) | ||
| Surgery plus postoperative CT or RT/CRT | 495 (36.9%) | 700 (59.8%) | 903 (49.0%) | 292 (43.6%) | 475 (36.9%) | 428 (77.1%) | 20 (37.0%) | 272 (44.2%) | ||
CRT, chemoradiotherapy; CT, chemotherapy; KPS, Karnofsky Performance Status; MIE, minimally invasive oesophagectomy; OO, open oesophagectomy; RT, radiotherapy; TNM, tumour, node, metastasis.