TABLE 2.
Univariate overall survival (N = 1457)
| Variable | HR (95% CI) | P value |
|---|---|---|
| Age at diagnosis | 1.03 (1.02–1.04) | <.001 |
| Charleson-Deyo comorbidity score (ref: 0) | ||
| 1 | 1.18 (0.94–1.47) | .08 |
| ≥2 | 1.44 (1.00–2.09) | |
| Insurance (ref: private) | ||
| Government | 1.55 (1.29–1.86) | <.001 |
| Uninsured | 1.29 (0.82–2.03) | |
| Mandible primary | 0.93 (0.77–1.13) | .48 |
| Tumor size in mm (ref: <10) | <.001 | |
| 10–19 | 1.22 (0.74–2.01) | |
| 20–29 | 1.26 (0.76–2.09) | |
| 30–39 | 1.96 (1.22–3.17) | |
| 40–49 | 1.84 (1.09–3.08) | |
| ≥50 | 2.55 (1.48–4.40) | |
| Grade (ref: low) | .001 | |
| Intermediate | 1.13 (0.93–1.37) | |
| High | 1.61 (1.23–2.09) | |
| Thickness or depth of invasion in mm | 1.00 (1.00–1.01) | .29 |
| Bone invasion | 1.02 (0.86–1.21) | .84 |
| T-stage 3 or 4 | 1.07 (0.84–1.37) | .56 |
| Positive surgical margin | 1.40 (1.18–1.66) | <.001 |
| Lymphovascular invasion | 1.47 (1.20–1.80) | <.001 |
| N-stage 2 or 3 | 2.32 (1.96–2.73) | <.001 |
| Level IV or V nodal metastasis | 2.80 (2.03–3.84) | <.001 |
| Extranodal extension | 2.10 (1.74–2.54) | <.001 |
| Number of NCCN risk factors | 1.43 (1.33–1.55) | <.001 |
| PORT | 0.83 (0.70–0.98) | .02 |
| Chemotherapy | 1.24 (1.00–1.53) | .05 |
Notes: Hazard ratios (HR), confidence intervals (CI), and P-values are from Cox proportional hazards models. Postoperative radiotherapy (PORT) and chemotherapy were assessed as time-varying. Other insignificant prognostic factors included gender (P = .63), diagnosis year (P = .67), race (P = .79), income (P = .29), education (P = .37), facility type (P = .45), and facility location (P = .35).