Long-term survival and risk factors in esophageal squamous cell carcinoma: A Kaplan-Meier and cox regression study

Table 2 Univariate and multivariate Cox regression equations affecting prognosis of patients with esophageal squamous cell carcinoma

Factors	Univariate Cox		Multivariate Cox
	HR (95%CI)	P value	HR (95%CI)	P value
Gender	1.197 (0.896-1.599)	0.225	-	-
Age	0.862 (0.532-1.398)	0.548	-	-
BMI	1.111 (1.032-1.197)	0.005	1.137 (1.054-1.226)	0.001
Tumor location
Upper segments	1	-	1	-
Middle segments	0.521 (0.287-0.944)	0.032	0.441 (0.240-0.810)	0.008
Lower segments	0.399 (0.177-0.901)	0.027	0.328 (0.144-0.750)	0.008
Degree of differentiation
Well-differentiated	1	-	-	-
Poorly differentiated	3.045 (0.712-13.015)	0.133	-	-
Moderately differentiated	2.265 (0.552-9.302)	0.257	-	-
Perineural invasion	7.947 (3.079-20.513)	< 0.001	13.381 (4.899-36.547)	< 0.001
Tumor length	1.011 (0.994-1.029)	0.196	-	-
Tumor width	1.014 (0.991-1.037)	0.240	-	-
Retrieved lymph nodes number	1.008 (0.983-1.033)	0.551	-	-
Smoking	1.947 (1.135-3.339)	0.016	2.415 (1.388-4.203)	0.002
Drinking	1.510 (0.753-3.030)	0.246	-	-

HR: Hazard ratio; 95%CI: 95% confidence interval; BMI: Body mass index.