Table 2. Multivariable cox regression analysis of OS in the matched cohort.

Variables	HR	95% CI lower	95% CI upper	P value
Gender (male vs. female)	0.911	0.689	1.205	0.514
Age	0.996	0.986	1.007	0.484
Tumor location
Lower	Ref	Ref	Ref	Ref
Middle	0.932	0.678	1.281	0.662
Upper	1.159	0.864	1.555	0.325
Tumor size (≥5 vs. <5 cm)	1.257	0.970	1.629	0.084
Differentiated (high vs. low)	1.613	1.230	2.115	<0.001
Chemotherapy	0.091	0.065	0.126	<0.001
pT stage
pT1 stage	Ref	Ref	Ref	Ref
pT2 stage	0.617	0.216	1.763	0.368
pT3 stage	1.442	0.554	3.755	0.453
pT4a stage	1.857	0.739	4.664	0.188
pT4b stage	2.813	1.090	7.257	0.032
pN stage
pN0 stage	Ref	Ref	Ref	Ref
pN1 stage	5.920	2.710	12.933	<0.001
pN2 stage	5.323	2.752	10.296	<0.001
pN3a stage	8.524	4.378	16.597	<0.001
pN3b stage	7.999	4.030	15.877	<0.001
TD	1.594	1.224	2.077	<0.001

OS, overall survival; HR, hazard ratio; CI, confidence interval; TD, tumor deposit.