Table 2. Demographic and clinical characteristics.
| Whole cohort N = 541 | Stratified by HPV N = 528 | ||||
|---|---|---|---|---|---|
| HPV-N = 378 | HPV+N = 150 | ||||
| Variable | N (%) | N (%) | N (%) | p-Value | |
| Age [Mean (std)] | Years | 53.5 (10.4) | 52.7 (10.1) | 55.5 (10.6) | 0.004 |
| Age | 21–40 | 42 (8%) | 32 (8%) | 9 (6%) | 0.18 |
| 41–60 | 358 (66%) | 255 (67%) | 94 (63%) | ||
| 61 to 86 | 141 (26%) | 91 (24%) | 47 (31%) | ||
| Stage | 1 | 29 (5%) | 22 (6%) | 7 (5%) | 0.40 |
| 2 | 68 (13%) | 47 (12%) | 20 (13%) | ||
| 3 | 84 (16%) | 61 (16%) | 16 (11%) | ||
| 4 | 359 (66%) | 248 (66%) | 106 (71%) | ||
| T-stage | 1 | 64 (12%) | 47 (12%) | 15 (10%) | 0.008 |
| 2 | 187 (35%) | 117 (31%) | 69 (46%) | ||
| 3 | 108 (20%) | 75 (20%) | 27 (18%) | ||
| 4 | 181 (34%) | 139 (37%) | 38 (26%) | ||
| N-stage | 0 | 169 (31%) | 122 (32%) | 41 (28%) | 0.22 |
| 1 | 77 (14%) | 59 (16%) | 16 (11%) | ||
| 2 | 246 (46%) | 165 (44%) | 77 (52%) | ||
| 3 | 48 (9%) | 32 (8%) | 15 (10%) | ||
| Disease Site | Soft Palate | 132 (24%) | 111 (29%) | 19 (13%) | <0.0001 |
| Tongue Base | 90 (17%) | 67 (18%) | 22 (15%) | ||
| Tonsil | 315 (58%) | 196 (52%) | 109 (73%) | ||
| Oropharynx, Other | 4 (1%) | 4 (1%) | 0 (0%) | ||
| Initial Treatment | Chemoradiation | 403 (75%) | 279 (75%) | 114 (77%) | 0.29 |
| Radiation | 89 (17%) | 59 (16%) | 27 (18%) | ||
| Surgery | 43 (8%) | 35 (9%) | 8 (5%) | ||
| Risk Factors | |||||
| Alcohol | Yes | 278 (51%) | 213 (56%) | 56 (37%) | <0.0001 |
| Smoke | Yes | 448 (83%) | 339 (90%) | 97 (65%) | <0.0001 |
| Betel Quid | Yes | 349 (65%) | 285 (75%) | 53 (35%) | <0.0001 |
| Alcohol and/or Smoke and/or Betel Quid | Yes | 468 (87%) | 351 (93%) | 105 (70%) | <0.0001 |
| Outcomes | |||||
| Death | 310 | 237 | 65 | ||
| Recurrence | 99 | 82 | 12 | ||
| Neck Recurrence | 82 | 67 | 13 | ||
| Metastasis | 55 | 39 | 13 | ||
HPV positivity is defined as HPV DNA-positive and/or p16-positive. p-values derived from t-test (continuous measures) or Chi-square test (categorical) by HPV status, missing values were excluded. TNM classification, according to the 7th AJCC staging edition: "T" (T classification), "N" (N classification), and "Stage" (overall stage). Because all cases were presented with no metastasis (M0), there is no heading for M. The individual variables "Alcohol", "Smoke, and "Betel Quid" were not adjusted for exposure to the other two risk factors.