Characteristics | Training cohort (N = 141) | p value | Independent cohort (N = 103) | p value | ||
---|---|---|---|---|---|---|
Low risk | High risk | Low risk | High risk | |||
n (%) | n (%) | n (%) | n (%) | |||
Age | ||||||
 ≤ 59 | 37 (52.1%) | 35 (50.0%) | 0.802 | 29 (55.8%) | 25 (49.0%) | 0.493 |
 > 59 | 34 (47.9%) | 35 (50.0%) |  | 23 (44.2%) | 26 (51.0%) |  |
Gender | ||||||
 Male | 58 (81.7%) | 54 (77.1%) | 0.500 | 36 (69.2%) | 38 (74.5%) | 0.660 |
 Female | 13 (18.3%) | 16 (22.9%) |  | 16 (30.8%) | 13 (25.5%) |  |
Tobacco use | ||||||
 Yes | 49 (69.0%) | 46 (65.7%) | 0.680 | 31 (59.6%) | 35 (64.1%) | 0.413 |
 No | 22 (31.0%) | 24 (34.3%) |  | 21 (40.4%) | 16 (35.9%) |  |
Alcohol use | ||||||
 Yes | 34 (47.9%) | 27 (38.6%) | 0.260 | 22 (42.3%) | 18 (35.3%) | 0.546 |
 No | 37 (52.1%) | 43 (61.4%) |  | 30 (57.7%) | 33 (64.7%) |  |
Tumor location | ||||||
 Upper | 6 (8.5%) | 7 (10.0%) | 0.510 | 2 (3.8%) | 6 (11.8%) | 0.210 |
 Middle | 51 (71.8%) | 44 (62.9%) |  | 32 (61.5%) | 33 (64.7%) |  |
 Lower | 14 (19.7%) | 19 (27.1%) |  | 18 (34.6%) | 12 (23.5%) |  |
Tumor size | ||||||
 ≤ 4 | 48 (67.6%) | 46 (65.7%) | 0.810 | 33 (63.5%) | 30 (58.8%) | 0.629 |
 > 4 | 23 (32.4%) | 24 (32.3%) |  | 19 (36.5%) | 21 (41.2%) |  |
N stage | ||||||
 N0 | 40 (56.3%) | 26 (37.1%) | 0.050 | 35 (67.3%) | 29 (56.9%) | 0.240 |
 N1 | 22 (31.0%) | 23 (32.9%) |  | 11 (21.2%) | 11 (21.6%) |  |
 N2 | 6 (8.5%) | 14 (20.0%) |  | 6 (11.5%) | 7 (13.7%) |  |
 N3 | 3 (4.2%) | 7 (10.0%) |  | 0 (0.0%) | 4 (7.8%) |  |
TNM stage | ||||||
 I | 2 (2.81%) | 2 (2.86%) | 0.579 | 8 (15.4%) | 2 (3.9%) | 0.131 |
 II | 34 (47.9%) | 39 (55.7%) |  | 28 (53.8%) | 29 (56.9%) |  |
 III | 35 (49.3%) | 28 (40.0%) |  | 16 (30.8%) | 20 (39.2%) |  |
Survival status | ||||||
 Survival cases | 50 (70.4%) | 20 (28.6%) | < 0.001 | 32 (61.5%) | 11 (21.6%) | < 0.001 |
 Death cases | 21 (29.6%) | 50 (71.4%) |  | 20 (38.5%) | 40 (78.4%) |  |