Table 2. Summary of significant prognostic factors in multivariate analysis.
| The original unmatched cohort | The propensity-matched cohort | |||
|---|---|---|---|---|
| Hazard ratio (95% CI) | P† | Hazard ratio (95% CI) | P‡ | |
| Overall survival | ||||
| IMRT versus 2DCRT | 1.26 (0.86-1.87) | 0.240 | 1.31 (0.78-2.20) | 0.313 |
| Age (continuous) | 1.06 (1.05-1.07) | <0.001 | 1.06 (1.04-1.09) | <0.001 |
| T-stage | 1.79 (1.51-2.11) | <0.001 | 1.72 (1.28-2.33) | <0.001 |
| N-stage | 2.09 (1.67-2.61) | <0.001 | 2.02 (1.42-2.88) | <0.001 |
| Locoregional relapse-free survival | ||||
| IMRT versus 2DCRT | 1.25 (0.76-2.07) | 0.381 | 1.20 (0.64-2.23) | 0.576 |
| T-stage | 1.36 (1.10-1.68) | 0.004 | 1.23 (0.90-1.67) | 0.194 |
| N-stage | 1.67 (1.24-2.25) | 0.001 | 1.89 (1.29-2.77) | 0.001 |
| Distant metastasis-free survival | ||||
| IMRT versus 2DCRT | 0.89 (0.55-1.44) | 0.629 | 0.98 (0.53-1.81) | 0.939 |
| Age (continuous) | 1.02 (1.01-1.04) | 0.005 | 1.03 (1.00-1.05) | 0.028 |
| T-stage | 1.84 (1.47-2.30) | <0.001 | 2.06 (1.54-2.77) | <0.001 |
| N-stage | 2.43 (1.80-3.29) | <0.001 | 2.26 (1.54-3.32) | <0.001 |
Abbreviations: CI = confidence interval, 2DCRT = two-dimensional conventional radiotherapy, IMRT = intensity-modulated radiotherapy
†
Adjusted for age (continuous), sex, histology, immunoglobulin A against viral capsid antigen (<80/80-320/≥320), immunoglobulin A against early antigen (<10/10-40/≥40), T-stage and N-stage by forward selection.
‡
Adjusted for the same covariates by forward selection with a robust variance estimator to account for the clustering within matched pair.