Table 3.
Univariate and multivariate analyses for overall survival (OS)
| Characteristics | Univariate analysis | Multivariate analysis | ||||
|---|---|---|---|---|---|---|
| HR | 95% CI | P | HR | 95% CI | P | |
| Gender | ||||||
| Female vs. male | 1.275 | 0.62-2.623 | 0.508 | |||
| Age (years) | ||||||
| ≥ 45 vs. < 45 | 1.199 | 0.848-1.694 | 0.304 | |||
| Overall stage | ||||||
| III + IVB vs. I + II | 1.373 | 0.641-2.943 | 0.415 | |||
| T category | ||||||
| T3-4 vs. T1-2 | 1.029 | 0.684-1.549 | 0.891 | |||
| N category | ||||||
| N2-3 vs. N0-1 | 1.913 | 1.572-2.326 | < 0.001 | 1.467 | 1.175-1.832 | 0.001 |
| Pretreatment ALP (U/L) | ||||||
| ≥ 110 vs. < 110 | 2.517 | 1.438-4.406 | 0.001 | 1.720 | 1.199-2.467 | 0.003 |
| Pretreatment EBV DNA (copies ml-1) | ||||||
| ≥ 6,750 vs. < 6,750 | 1.933 | 1.362-2.745 | < 0.001 | 1.635 | 1.131-2.363 | 0.009 |
| IMRT after metastasis | ||||||
| No vs. yes | 1.470 | 1.009-2.143 | 0.045 | 1.578 | 1.077-2.314 | 0.019 |
| Vertebral metastasis | ||||||
| Present vs. absent | 2.269 | 1.531-3.363 | < 0.001 | 1.997 | 1.321-3.020 | 0.001 |
| Number of metastatic sites | ||||||
| ≥ 3 vs. < 3 | 1.539 | 1.078-2.198 | 0.018 | 1.531 | 1.056-2.220 | 0.025 |
| DFI (months) | ||||||
| ≥ 13 vs. < 13 | 2.824 | 1.983-4.023 | < 0.001 | 2.868 | 1.987-4.139 | 0.001 |
Abbreviations: HR = unadjusted hazard ratio; CI = confidence interval; IMRT = intensity modulated radiotherapy; DFI = disease-free interval to bone-only metastases.