2.

Multivariate Cox proportional hazards model of DFS

Variables	DFS
	HR	95% CI	P
DFS, disease-free survival; HR, hazard ratio; 95% CI, 95% confidence interval; NOS, not otherwise specified.
Pathologic type
Squamous carcinoma vs. carcinoma NOS	0.436	0.211–0.899	0.025
Adenocarcinoma vs. carcinoma NOS	0.608	0.299–1.235	0.169
Mixed vs. carcinoma NOS	1.023	0.408–2.561	0.962
Large cell carcinoma vs. carcinoma NOS	0.289	0.035–2.388	0.249
Clinical stage
IB vs. IIIB	0.243	0.109–0.542	0.001
IIA vs. IIIB	0.375	0.192–0.731	0.004
IIB vs. IIIB	0.386	0.179–0.834	0.015
IIIA vs. IIIB	0.588	0.364–0.948	0.029
Radiotherapy (yes vs. no)	0.674	0.515–0.883	0.004