Table 2.
Multivariable analysis of prognostic factors for OS, PFS, LRFS, and DMFS
| Characteristic | HR (95% CI) | P‐value |
|---|---|---|
| Overall survival | ||
| Age | 1.592 (1.191‐2.130) | 0.002 |
| Gender | 2.419 (1.413‐3.268) | <0.001 |
| Smoking | 1.086 (0.925‐1.275) | 0.314 |
| Family history of NPC | 0.809 (0.519‐1.261) | 0.349 |
| T stage | ||
| T2 vs T1 | 1.439 (0.705‐2.938) | 0.317 |
| T3 vs T1 | 1.945 (0.980‐3.859) | 0.057 |
| N stage | ||
| N1 vs N0 | 1.033 (0.673‐1.585) | 0.883 |
| N2 vs N0 | 1.506 (0.967‐2.345) | 0.070 |
| EBV‐DNA level | 3.581 (2.503‐5.125) | <0.001 |
| Treatment method | 0.582 (0.430‐0.788) | <0.001 |
| Progression free survival | ||
| Age | 1.127 (0.911‐1.393) | 0.270 |
| Gender | 1.543 (1.167‐2.039) | 0.002 |
| Smoking | 1.025 (0.908‐1.159) | 0.687 |
| Family history of NPC | 0.881 (0.638‐1.217) | 0.442 |
| T stage | ||
| T2 vs T1 | 1.474 (0.889‐2.442) | 0.132 |
| T3 vs T1 | 1.675 (1.029‐2.727) | 0.038 |
| N stage | ||
| N1 vs N0 | 1.003 (0.737‐1.364) | 0.986 |
| N2 vs N0 | 1.191 (0.859‐1.653) | 0.295 |
| EBV‐DNA level | 3.353 (2.607‐4.311) | <0.001 |
| Treatment method | 0.708 (0.562‐0.893) | 0.004 |
| Loco‐regional relapse‐free survival | ||
| Age | 1.019 (0.718‐1.446) | 0.916 |
| Gender | 1.605 (1.018‐2.531) | 0.042 |
| Smoking | 0.991 (0.810‐1.213) | 0.931 |
| Family history of NPC | 1.256 (0.787‐2.005) | 0.340 |
| T stage | ||
| T2 vs T1 | 2.519 (0.997‐6.364) | 0.051 |
| T3 vs T1 | 2.028 (0.808‐5.088) | 0.132 |
| N stage | ||
| N1 vs N0 | 0.941 (0.589‐1.503) | 0.799 |
| N2 vs N0 | 0.924 (0.547‐1.562) | 0.768 |
| EBV‐DNA level | 3.049 (2.041‐4.555) | <0.001 |
| Treatment method | 0.590 (0.404‐0.861) | 0.006 |
| Distant metastasis‐free survival | ||
| Age | 1.061 (0.811‐1.387) | 0.667 |
| Gender | 1.479 (1.039‐2.103) | 0.030 |
| Smoking | 1.019 (0.872‐1.190) | 0.817 |
| Family history of NPC | 0.844 (0.556‐1.280) | 0.425 |
| T stage | ||
| T2 vs T1 | 1.064 (0.577‐1.963) | 0.842 |
| T3 vs T1 | 1.539 (0.866‐2.734) | 0.142 |
| N stage | ||
| N1 vs N0 | 1.246 (0.806‐1.927) | 0.323 |
| N2 vs N0 | 1.593 (1.015‐3.500) | 0.043 |
| EBV‐DNA level | 3.908 (2.794‐5.467) | <0.001 |
| Treatment method | 0.782 (0.580‐1.055) | 0.107 |
A Cox proportional hazard model was used to perform multivariate analyses. All variables were transformed into categorical variables. HRs were calculated for Age (years) (>47 vs ≤47); Gender (Male vs Female); Smoking (Yes vs No); Family history of NPC (Yes vs No); EBV DNA level (>1460 copies/mL vs ≤1460 copies/mL) and Treatment method (CCRT vs IMRT alone).
Abbreviations: CI, confidence interval; DMFS, distant metastasis‐free survival; EBV, Epstein–Barr virus; HR, hazard ratio; NPC, nasopharyngeal carcinoma; OS, Overall survival; LRFS, locoregional relapse‐free survival; PFS, progression free survival.