Table S1. Multivariate analyses of prognostic factors for overall survival and recurrence-free survival in the patients without lymph node metastasis.

Variable	Hazard ratio	95% CI	P value
OS
Cavity wall thickness (mm): >15 vs. ≤15	4.69	1.12–19.69	0.035*
RFS
Age (years): >70 vs. ≤70	2.98	0.87–10.17	0.081
Cavity wall thickness (mm): >15 vs. ≤15	5.45	1.59–18.64	0.007*

*, P<0.05. 95% CI, 95% confidence interval; OS, overall survival; RFS, recurrence-free survival.