Table 5. Univariable and multivariable analysis for distant metastasis-free survival.
| Univariable analysis | Multivariable analysisa | |||||
|---|---|---|---|---|---|---|
| HR | 95% CI | P | HR | 95% CI | P | |
| Age | 1.006 | 0.968–1.045 | 0.775 | ND | ||
| Sex (male as reference) | 0.676 | 0.241–1.896 | 0.457 | ND | ||
| T-classification | ||||||
| T1/T2 vs. T3/T4 | 0.392 | 0.148–1.034 | 0.058 | 0.495 | 0.183–1.335 | 0.165 |
| N-classification | ||||||
| N0N1 vs. N2/N3 | 0.486 | 0.188–1.255 | 0.136 | ND | ||
| Overall stage | ||||||
| I/II vs. III/IVA-B | 0.550 | 0.181–1.670 | 0.291 | ND | ||
| IMRT alone | 2.899 | 0.386–21.739 | 0.301 | ND | ||
| Concurrent chemoradiation | 1.060 | 0.304–3.689 | 0.927 | ND | ||
| Induction chemotherapy then concurrent chemoradiation | 0.217 | 0.083–0.568 | 0.003 | 0.219 | 0.080–0.565 | 0.003 |
| Concurrent chemoradiation then adjuvant chemotherapy | 0.472 | 0.177–1.263 | 0.135 | ND | ||
| PD-L1 expression level | ||||||
| PD-L1 1+ | 0.533 | 0.155–1.835 | 0.319 | ND | ||
| PD-L1 2+ | 0.782 | 0.225–2.725 | 0.700 | ND | ||
Abbreviations: CI, confidence interval; HR, hazard ratio; IMRT, intensity-modulated radiation therapy; ND, not done; PD-L1, programmed death-ligand 1.
aOnly covariates found significant (P < 0.1) in the univariable analysis were considered in the multivariable analysis.