Table 2.
Multivariate analysis using step-wise method
| Characteristic | HR | 95% CI | P-value |
|---|---|---|---|
| EBV DNA level | 2.13 | 1.58–2.88 | < 0.001 |
| Tumor response | 1.34 | 1.02–1.77 | 0.036 |
| N stage | 1.40 | 1.02–1.91 | 0.036 |
| Metastatic site | |||
| Lung vs. Bone | 0.89 | 0.58–1.36 | 0.589 |
| Liver vs. Bone | 1.00 | 0.66–1.51 | 0.993 |
| Distant nodal vs. Bone | 0.98 | 0.52–1.84 | 0.956 |
| Multiple vs. Bone | 2.39 | 1.77–3.23 | < 0.001 |
| LRRT | 0.76 | 0.59–0.98 | 0.037 |
All factors were involved in the analysis and five factors remained
Abbreviations: EBV Epstein-Barr virus, HR hazard ratio, CI confidence interval, LRRT locoregional radiotherapy
All potential prognostic factors were involved in the analysis and five factors remained
HRs were calculated for N stage (N2–3 vs. N0–1); LRRT (Yes vs. No); EBV DNA level (Detectable vs. Undetectable) and Tumor response (SD/PD vs. CR/PR)