Table 1 Clinical and pathologic characteristics of patients with HNSCC in the training, Internal validation, and external validation cohorts
Clinical Characteristics |  | Training Cohort (n = 267) | Internal validation cohort (n = 115) | External validation cohort (n = 134) |  | P value |
|---|---|---|---|---|---|---|
Age (mean ± SD, years) |  |  61.70 ± 8.50 |  59.85 ± 8.16 |  58.76 ± 8.63 |  | 0.003 |
Histological differentiation | Â | Â | Â | Â | Â | 0.505 |
| Â | Well | 31 (11.61%) | 11 (9.57%) | 14 (10.45%) | Â | Â |
| Â | Moderately | 115 (43.07%) | 48 (41.74%) | 47 (35.07%) | Â | Â |
| Â | Poorly | 121(45.32%) | 56 (48.69%) | 73 (54.48%) | Â | Â |
T stage | Â | Â | Â | Â | Â | 0.043 |
| Â | 2 | 89 (33.33%) | 30 (26.09%) | 46 (34.33%) | Â | Â |
| Â | 3 | 120 (44.94%) | 46 (40.00%) | 46 (34.33%) | Â | Â |
| Â | 4 | 58 (21.73%) | 39 (33.91%) | 42 (31.34%) | Â | Â |
N stage | Â | Â | Â | Â | Â | 0.321 |
| Â | 0 | 85 (31.84%) | 34 (29.57%) | 33 (24.63%) | Â | Â |
| Â | 1 | 83 (31.09%) | 31 (26.96%) | 40 (29.85%) | Â | Â |
| Â | 2 | 92 (34.46%) | 42 (36.52%) | 53 (39.55%) | Â | Â |
| Â | 3 | 7 (2.61%) | 8 (6.95%) | 8 (5.97%) | Â | Â |
Smoking | Â | Â | Â | Â | Â | 0.519 |
| Â | No | 72 (27.00%) | 29 (25.22%) | 42 (31.34%) | Â | Â |
| Â | Yes | 195 (73.00%) | 86 (74.78%) | 92 (68.66%) | Â | Â |
Drink | Â | Â | Â | Â | Â | 0.758 |
| Â | No | 185(85.5%) | 79 (68.70%) | 88 (65.67%) | Â | Â |
| Â | Yes | 82 (14.5%) | 36 (31.30%) | 46 (34.33%) | Â | Â |
Sex | Â | Â | Â | Â | Â | 0.196 |
| Â | Male | 238 (89.14%) | 109 (76.20%) | 123 (91.79%) | Â | Â |
| Â | Female | 29(10.86%) | 6 (23.80%) | 11 (8.21%) | Â | Â |