Table 2.
Predictors of locoregional control (LRC), disease‐free survival (DFS), and overall survival (OS) on multivariate analysis (MVA) of entire cohort
| Multivariate analysis of outcomes | LRC | DFS | OS | |||
|---|---|---|---|---|---|---|
| MVA (P) | HR (95% CI) | MVA (P) | HR (95% CI) | MVA (P) | HR (95% CI) | |
| Location of RT | ||||||
| HVC | <0.001 | 0.57 (0.44‐0.72) | 0.013 | 0.78 (0.63‐0.95) | 0.898 | — |
| LVC | ||||||
| Residence | ||||||
| Elsewhere | 0.203 | — | <0.001 | 1.32 (1.13‐1.54) | <0.001 | 1.44 (1.24‐1.68) |
| County of HVC | ||||||
| Tobacco use | ||||||
| Current | 0.246 | — | <0.001 | REF | <0.001 | REF |
| Former | 0.013 | 0.83 (0.71‐0.96) | <0.001 | 0.75 (0.64‐0.88) | ||
| Never | 0.001 | 0.59 (0.44‐0.8) | <0.001 | 0.45 (0.32‐0.63) | ||
| Unknown use | 0.001 | 0.66 (0.51‐0.84) | 0.001 | 0.65 (0.5‐0.83) | ||
| HPV/P16 status | ||||||
| HPV (−) | <0.001 | REF | 0.001 | REF | <0.001 | — |
| HPV (+) | 0.001 | 0.16 (0.06‐0.47) | 0.002 | 0.35 (0.18‐0.68) | <0.001 | 0.22 (0.11‐0.48) |
| Unknown HPV status | 0.314 | — | 0.162 | — | 0.16 | |
| Primary site | ||||||
| Oral cavity/LIPS | <0.001 | REF | <0.001 | REF | <0.001 | REF |
| Oropharynx | <0.001 | 0.27 (0.19‐0.39) | <0.001 | 0.44 (0.34‐0.56) | <0.001 | 0.46 (0.36‐0.6) |
| Larynx | <0.001 | 0.32 (0.22‐0.47) | <0.001 | 0.56 (0.44‐0.7) | <0.001 | 0.61 (0.48‐0.78) |
| Hypopharynx | 0.012 | 0.51 (0.3‐0.86) | 0.429 | — | 0.534 | — |
| Nasopharynx | <0.001 | 0.16 (0.08‐0.33) | <0.001 | 0.42 (0.28‐0.64) | <0.001 | 0.43 (0.28‐0.66) |
| Nasal cavity/sinus | 0.089 | 0.63 (0.38‐1.07) | 0.266 | — | 0.088 | 0.69 (0.45‐1.06) |
| Salivary | 0.989 | — | 0.506 | — | 0.093 | 1.52 (0.93‐2.48) |
| Unknown primary | 0.937 | — | 0.665 | — | 0.345 | — |
| Tumor stage | ||||||
| T1 | <0.001 | REF | <0.001 | REF | <0.001 | REF |
| T2 | 0.278 | — | 0.001 | 1.46 (1.16‐1.85) | 0.001 | 1.52 (1.18‐1.94) |
| T3 | 0.027 | 1.55 (1.05‐2.29) | <0.001 | 1.84 (1.45‐2.35) | <0.001 | 1.96 (1.52‐2.53) |
| T4 | <0.001 | 2.36 (1.63‐3.41) | <0.001 | 2.47 (1.95‐3.12) | <0.001 | 2.72 (2.12‐3.49) |
| T0/TX | 0.935 | — | 0.978 | — | 0.997 | — |
| Nodal stage | ||||||
| N0 | 0.236 | — | <0.001 | REF | <0.001 | REF |
| N1 | 0.716 | 0.116 | — | 0.009 | 1.35 (1.08‐1.7) | |
| N2 | 0.47 | <0.001 | 1.52 (1.28‐1.81) | <0.001 | 1.69 (1.41‐2.03) | |
| N3 | 0.105 | <0.001 | 2.63 (1.93‐3.59) | <0.001 | 3.09 (2.26‐4.23) | |
| Chemotherapy | ||||||
| Chemo (+) | 0.876 | — | 0.221 | — | 0.446 | — |
| Chemo (−) | ||||||
| RT duration (wk) | ||||||
| ≤7 | 0.094 | REF | 0.004 | REF | 0.001 | REF |
| >7 | 0.081 | 1.22 (0.98‐1.53) | 0.001 | 1.27 (1.1‐1.47) | 0.001 | 1.3 (1.12‐1.5) |
| Unknown duration | 0.403 | 0.318 | — | 0.022 | 1.6 (1.07‐2.38) | |
| IMRT | ||||||
| IMRT (−) | 0.242 | — | 0.011 | REF | 0.103 | — |
| IMRT (+) | 0.003 | 0.77 (0.65‐0.91) | ||||
| Unknown IMRT status | 0.154 | — | ||||
| Total RT dose (NCCN) | ||||||
| <60/66 Gy | 0.71 | — | 0.135 | — | <0.001 | REF |
| ≥60/66 Gy | <0.001 | 0.58 (0.46‐0.74) | ||||
| Unknown dose | 0.117 | — | ||||
| DTI (d) | ||||||
| 46+ | 0.56 | — | 0.28 | — | 0.368 | — |
| ≤45 | ||||||
| Age (y) | 0.139 | — | <0.001 | 1.02 (1.02‐1.03) | <0.001 | 1.03 (1.02‐1.04) |
DFS, disease‐free survival; DTI, diagnosis to treatment initiation; HVC, high‐volume center; HPV, human papillomavirus; IMRT, intensity‐modulated radiotherapy; LRC, locoregional control; LVC, low‐volume center; MVA, multivariate analysis; OS, overall survival; RT, radiation.