Table 1. A univariate analysis of factors affecting the overall survival rate.

	Univariate analysis
	N	5-year survival rate (%)	P value
Age (years)			<0.001
<65	570	69.6
≥65	947	56.9
Gender			<0.001
Male	1055	59.2
Female	462	67.0
Tumor size			<0.001
< 5 cm	816	77.7
≥ 5 cm	701	42.8
Lymphovascular invasion			<0.001
Absent	716	81.9
Present	801	43.5
7th AJCC edition pTNM stage			<0.001
Stage IA	450	88.5
Stage IB	166	81.9
Stage IIA	188	73.5
Stage IIB	156	68.9
Stage IIIA	150	47.3
Stage IIIB	243	24.1
Stage IIIC	164	15.4
8th AJCC edition pTNM stage			<0.001
Stage IA	450	88.5
Stage IB	166	81.9
Stage IIA	188	73.5
Stage IIB	153	69.0
Stage IIIA	200	42.1
Stage IIIB	171	26.9
Stage IIIC	189	13.6