Table 4.

Cox regression analysis for various potential prognostic factors in overall survival

Variable	Unfavorable/ favorable characteristics	No. of Patients	Univariate (U)			Multivariate (M)
			Relative risk	95% confidential interval	P value	Relative risk	95% confidential interval	P value
Grade	4,3 / 2,1	14 / 36	2.579	1.425–4.667	0.0017	2.171	0.956–4.931	0.0639
pT	4,3 / 2,1	13 / 37	6.666	1.548–28.711	0.0109	4.222	0.745–23.922	0.1036
pN	2,1 / 0	18 / 32	2.365	1.095–5.110	0.0285	1.366	0.732–1.293	0.5042
Mutation of Nrf2	(+) / (−)	5 / 45	3.015	1.030–8.824	0.0440	2.791	0.610–12.768	0.1859
SNPs of rs6721961	CA, AA / CC	20 / 30	2.139	1.010–4.530	0.0469	1.167	0.857–1.351	0.7341
Expression of Nrf2	high / low	24 / 26	8.485	3.102–23.210	< 0.0001	6.435	1.964–21.087	0.0021
Mutation of Keap1	(+) / (−)	11 / 39	1.679	0.758–3.721	0.2016	1.122	0.891–1.347	0.8107