Table 3.

Cancer specific and overall survival comparing different treatment strategies stratified by tumor histology.

		Cancer specific survival		Overall survival
		PS-adjusted HR (95% CI)	p-value	PS-adjusted HR (95% CI)	p-value
Adenocarcinoma	Unimodal (ref. group) vs. bimodal therapy	0.68 (0.60–0.76)	<0.001	0.56 (0.50–0.62)	<0.001
	Surgery only (ref. group) vs. EBRT only	1.21 (1.03–1.42)	0.02	1.34 (1.15–1.55)	<0.001
	Surgery only vs. EBRT only,.first 7 months	0.81 (0.64–1.04)	0.10	0.71 (0.56–0.90)	0.005
	Surgery only vs. EBRT only, 8 to 60 months	1.40 (1.14–1.71)	0.001	1.64 (1.36–1.97)	<0.001
	Preoperative (ref. group) vs. postoperative EBRT	0.92 (0.76–1.12)	0.42	1.05 (0.88–1.25)	0.58
Squamous cell cancer	Unimodal (ref. group) vs. bimodal therapy	0.64 (0.53–0.79)	<0.001	0.59 (0.49–0.71)	<0.001
	Surgery only (ref. group) vs. EBRT only	1.13 (0.91–1.40)	0.27	1.09 (0.90–1.33)	0.38
	Surgery only vs. EBRT only,.first 7 months	0.86 (0.62–1.19)	0.36	0.68 (0.49–0.95)	0.02
	Surgery only vs. EBRT only, 8 to 60 months	1.18 (0.90–1.54)	0.24	1.19 (0.93–1.52)	0.18
	Preoperative (ref. group) vs. postoperative EBRT	1.38 (0.93–2.04)	0.11	1.38 (0.97–1.95)	0.08

Estimations for CSS were performed using competing-risks regression model while for OS, cox proportional hazard models were performed. For the calculation of the propensity score (PS), the following covariates were used: gender, age (≤65 years, >65 years), race, ethnicity, marital status, tumor grade, tumor location, tumor T-stage, histology, and year (5 consecutive groups). vs.=versus, EBRT = External beam radiotherapy, ref.=reference, HR=Hazard ratio, CI=95% confidence interval