Table 4.
Stepwise uni- and multi-variate analysis using Cox regression model for overall survival and disease-free survival
| Variable | Overall survival |
Disease-free survival |
||||||
|---|---|---|---|---|---|---|---|---|
| Univariable |
Multivariable |
Univariable |
Multivariable |
|||||
| Median (mo) | p-value | HR (95% CI) | p-value | Median (mo) | p-value | HR (95% CI) | p-value | |
| Age | 96 vs. 59 | 0.05 | 0.33 (0.11-0.98) | 0.046 | 96 vs. 12 | 0.02 | - | - |
| (< 65 yr vs. ≥ 65 yr) | ||||||||
| Tumor size | 73 vs. 18 | 0.16 | - | - | 59 vs. 10 | 0.14 | - | - |
| (< 4 cm vs. ≥ 4 cm) | ||||||||
| Differentiation | 69 vs. 59 | 0.65 | - | - | 69 vs. 30 | 0.76 | - | - |
| (MD vs. PD) | ||||||||
| T stage (T1-2 vs. T3-4) | 96 vs. 57 | 0.26 | - | - | 69 vs. 30 | 0.29 | - | - |
| N stage (N0-1 vs. N2-3) | 59 vs. 69 | 0.99 | - | - | 31 vs. 57 | 0.85 | - | - |
| Resection margin | 69 vs. 59 | 0.91 | - | - | 69 vs. 30 | 0.49 | - | - |
| (negative vs. closed or positive) | ||||||||
| Lymphovascular invasion | 69 vs. 59 | 0.72 | - | - | 30 vs. 59 | 0.48 | - | - |
| (no vs. yes) | ||||||||
| Perineural invasion | 59 vs. NR | 0.13 | - | - | 31 vs. NR | 0.12 | - | - |
| (no vs. yes) | ||||||||
| Extranodal extension | 69 vs. 59 | 0.9 | - | - | 31 vs. 30 | 0.9 | - | - |
| (no vs. yes) | ||||||||
| Total dose | 96 vs. 59 | 0.09 | - | - | 96 vs. 30 | 0.04 | 0.13 (0.02-0.7) | 0.02 |
| (> 59.4 Gy vs. ≤ 59.4 Gy) | ||||||||
| SOX2 gene amplification | 69 vs. 59 | 0.95 | - | - | 30 vs. 82 | 0.48 | - | - |
| (yes vs. no) | ||||||||
| SOX2 overexpression | 73 vs. 8 | 0.01 | 0.1 (0.02-0.5) | 0.005 | 57 vs. 5 | 0.08 | 0.15 (0.04-0.65) | 0.01 |
| (yes vs. no) | ||||||||
HR, hazard ratio; CI, confidence interval; MD, moderately differentiated; PD, poorly differentiated; NR, not reached.