Table 1 Patient characteristics
|  | p16-positive n = 72 (%) | p16-negative n = 590 (%) | p-value |
|---|---|---|---|
Median Age (years, range) | 58 (38–84) | 62 (20–95) | 0.252 |
 Age ≥ 65 | 24 (33) | 242 (41) | |
ECOG | |||
 0–1 | 67 (93) | 532 (90) | 0.528 |
 ≥ 2 | 5 (7) | 58 (10) | |
Sex | |||
 Male | 53 (74) | 441 (75) | 0.886 |
 Female | 19 (26) | 149 (25) | |
Smoking | |||
  Never | 28 (40) | 193 (35) | 0.427 |
  Ever | 42 (60) | 361 (65) | |
  Mean pack-year (+/−SD) | 23.9 (14.3) | 26.3 (18.2) | 0.418 |
 Missing | 2 | 36 | |
Site of primary tumor | |||
 Oral cavity | 12 (17) | 245 (41) | < 0.001 |
 Oropharynx | 38 (53) | 99 (17) | |
 Larynx | 13 (18) | 131 (22) | |
 Hypopharynx | 5 (7) | 89 (15) | |
 Paranasal sinus | 4 (6) | 23 (4) | |
 Unknown primary | 0 | 3 (1) | |
Site of primary tumor | |||
 Oropharynx | 38 (53) | 99 (17) | < 0.001 |
 Non-oropharynx | 34 (47) | 491 (83) | |
Histology grade | |||
 Well differentiated | 7 (12) | 194 (38) | < 0.001 |
 Moderately differentiated | 34 (57) | 226 (44) | |
 Poorly-differentiated | 13 (22) | 37 (7) | |
 Undifferentiated | 6 (10) | 59 (11) | |
 Non-specific type | 12 | 74 | |
Stage at Diagnosis (AJCC 7th) | |||
 I | 6 (8) | 85 (15) | 0.425 |
 II | 8 (11) | 52 (9) | |
 III | 11 (15) | 91 (15) | |
 IVa/b | 45 (63) | 325 (55) | |
 IVc | 2 (3) | 35 (6) | |
T-stage | |||
 1–2 | 36 (50) | 224 (38) | 0.057 |
 3–4 | 36 (50) | 360 (62) | |
 Tx | 0 | 6 | |
N-Stage | |||
 0 | 21 (29) | 261 (44) | 0.049 |
 1 | 14 (19) | 96 (16) | |
 2 | 33 (46) | 188 (32) | |
 3 | 4 (6) | 44 (8) | |
 Nx | 0 | 1 | |
Definitive treatment for locally advanced disease | |||
 Surgery alone | 23 (32) | 306 (54) | < 0.001 |
 Surgery with adjuvant CRT | 9 (14) | 83 (15) | |
 Definitive CRT | 39 (55) | 179 (31) | |