Table 2. Univariate and multivariate cox regression analyses for overall survival in patients with ESCC in primary cohort.

Variables	Univariate analysis		Multivariate analysis
	HR (95%CI)	P value	HR (95%CI)	P value
Sex
Male vs. Female	0.69 (0.43–1.13)	0.141
Age
≥ 60 years vs. < 60 years	0.94 (0.64–1.37)	0.737
Histological grade		0.002*		0.011*
Well differentiated	Ref.		Ref.
Moderately differentiated	2.90 (0.90–9.31)	0.074	1.77 (0.54–5.78)	0.346
Poorly or not differentiated	4.87 (1.52–15.59)	0.008*	2.99 (0.92–9.75)	0.069
Tumor location		0.900
Upper	Ref.
Middle	0.89 (0.41–1.96)	0.778
Lower	0.84 (0.38–1.88)	0.672
Examined lymph nodes
≥ 15 vs. < 15	0.81 (0.55–1.19)	0.285
T stage		< 0.001*		< 0.001*
T1	Ref.		Ref.
T2	2.12 (1.17–3.85)	0.013*	2.01 (1.10–3.68)	0.023*
T3	3.77 (2.20–6.47)	< 0.001*	3.46 (2.00–5.98)	< 0.001*
ZFAS1
Low vs. High	1.89 (1.28–2.79)	0.002*	1.59 (1.07–2.36)	0.022*