TCGA and Belgian cohort patients’ clinical characteristics
| Parameter | TCGA cohort, n=89 | Belgian cohort, n=99 |
| Sex | N (%) | N (%) |
| Female | 12 (13.5) | 24 (24.2) |
| Male | 77 (86.5) | 75 (75.8) |
| Age | Median (IQR) | Median (IQR) |
| 58.8 (53.4–67.975) | 61.4 (56.3–69.2) | |
| Histological type | N (%) | N (%) |
| Adenocarcinoma | 35 (39.3) | 61 (61.6) |
| Squamous cell carcinoma | 54 (60.7) | 38 (38.4) |
| Histological grade | N (%) | N (%) |
| Well differentiated | 14 (15.7) | 19 (19.2) |
| Moderately differentiated | 36 (40.45) | 58 (58.6) |
| Poorly differentiated | 27 (30.35) | 22 (22.2) |
| Unknown | 12 (13.5) | 0 (0) |
| Location | N (%) | N (%) |
| Upper third | 4 (4.5) | 15 (15.15) |
| Middle third | 21 (23.6) | 19 (19.2) |
| Lower third | 61 (68.5) | 65 (65.65) |
| Unspecified | 3 (3.4) | 0 (0) |
| Tumour depth | N (%) | N (%) |
| T1 | 15 (16.85) | 23 (23.2) |
| T2 | 25 (28.1) | 19 (19.2) |
| T3 | 45 (50.55) | 50 (50.5) |
| T4 | 4 (4.5) | 3 (3.05) |
| Unspecified | 0 (0) | 4 (4.05) |
| Lymph node metastasis | N (%) | N (%) |
| N0 | 36 (40.4) | 43 (43.4) |
| N1 | 40 (45) | 33 (33.3) |
| N2 | 8 (9) | 10 (10.1) |
| N3 | 4 (4.5) | 6 (6.05) |
| Unspecified | 1 (1.1) | 7 (7.05) |
| Smoker | N (%) | N (%) |
| Smoker | 46 (51.7) | 61 (61.6) |
| Non-smoker | 26 (29.2) | 37 (37.4) |
| Unspecified | 17 (19.1) | 1 (1) |
| Drinker | N (%) | N (%) |
| Drinker | 39 (43.8) | 51 (51.5) |
| Non-drinker | 12 (13.5) | 46 (46.5) |
| Unspecified | 38 (42.7) | 2 (2) |
| HGP | N (%) | N (%) |
| IGP | 41 (46) | 59 (59.6) |
| EGP | 48 (54) | 40 (40.4) |
EGP, expansive growth pattern; HGP, histopathological growth pattern; IGP, infiltrative growth pattern; TCGA, The Cancer Genome Atlas.