Table 1. Patient population and clinicopathological variables.
| Variable | No. (Percentage) |
| Median age (years) | 59.0 (range 18–82) |
| Gender | |
| Female | 23 (10.6%) |
| Male | 193 (89.4%) |
| Primary tumor sites | |
| Supraglottic | 96 (44.4%) |
| Glottic | 116 (53.7%) |
| Subglottic | 4 (1.9%) |
| Histologic differentiation | |
| Well | 84 (38.9%) |
| Moderate | 89 (41.2%) |
| Poor | 43 (19.9%) |
| Primary tumor | |
| T1 | 59 (27.3%) |
| T2 | 67 (31.0%) |
| T3 | 48 (22.2%) |
| T4 | 42 (19.4%) |
| Cervical lymph node metastasis | |
| N0 | 161 (74.5%) |
| N1 | 41 (19.0%) |
| N2 | 13 (6.0%) |
| N3 | 1 (0.5%) |
| Distant metastasis | |
| M0 | 211 (97.7%) |
| M1 | 5 (2.3%) |
| Clinical stage | |
| I | 56 (25.9%) |
| II | 48 (22.2%) |
| III | 59 (27.3%) |
| IV | 53 (24.5%) |
| Smoking status | |
| Yes | 132 (61.1%) |
| No | 84 (38.9%) |