Table 3.

Multivariate analysis using Cox proportional hazards model

Parameter	HR	95% CI	P value
OS
Receipt of chemotherapy (yes vs no)	0.41	0.21–0.80	.010
Tumor size (>2 cm vs ≤2 cm)	2.80	1.32–5.94	.008
Presence of nodal failure (yes vs no)	3.88	1.73–8.75	.001
DFS
Receipt of chemotherapy (yes vs no)	0.37	0.17–0.82	.014
Response of primary tumor (partial vs complete)	3.61	1.20–10.87	.023
LC
Total radiation dose (continuous variable)	0.71	0.54–0.94	.018

Abbreviations: CI = confidence interval; DFS = disease-free survival; HR = hazard ratio; LC = local control; OS = overall survival.

Statistically significant variables associated with OS, DFS, and LC are listed.