Table 3. Association between clinicopathological characteristics and DFS/OS by COX regression model analysis in ESCC patients with stage I and II disease.

	DFS						OS
	Univariate			Multivariate			Univariate			Multivariate
	HR	CI (95%)	P value	HR	CI (95%)	P value	HR	CI (95%)	P value	HR	CI (95%)	P value
Gender
Male	1			1			1			1
Female	0.964	0.622-1.492	0.868	1.190	0.762-1.861	0.445	0.982	0.629-1.534	0.936	1.214	0.770-1.913	0.403
Age
<60	1						1
≥60	1.068	0.735-1.551	0.729				1.047	0.715-1.531	0.814
Tumor site
Upper/middle	1						1
Low	0.920	0.631-1.340	0.663				0.930	0.632-1.369	0.712
Smoking
No	1						1
Yes	0.944	0.637-1.401	0.776				1.007	0.676-1.499	0.973
Necrosis
No	1						1
Yes	1.119	0.738-1.697	0.597				1.118	0.728-1.717	0.611
Differentiation
Well/Moderate	1			1			1			1
Poor	1.288	0.885-1.873	0.186	1.029	0.698-1.517	0.886	1.176	0.799-1.732	0.410	0.873	0.582-1.311	0.513
Invasion depth
I+II	1			1			1			1
III	0.987	0.637-1.527	0.952	1.560	0.933-2.609	0.090	1.073	0.691-1.666	0.753	1.686	0.996-2.855	0.052
Lymph node metastasis
No	1			1			1			1
Yes	2.474	1.649-3.711	<0.001*	2.469	1.565-3.895	<0.001*	2.694	1.790-4.057	<0.001*	2.899	1.824-4.606	<0.001*
Distant metastasis
No	1			1			1			1
Yes	6.275	3.996-9.854	<0.001*	6.131	3.769-9.971	<0.001*	6.162	3.911-9.708	<0.001*	6.389	3.884-10.509	<0.001*
Vessel involvement
No	1			1			1			1
Yes	1.159	0.674-1.995	0.594	0.825	0.474-1.436	0.497	1.133	0.647-1.985	0.662	0.812	0.459-1.438	0.475
Nerve involvement
No	1			1			1			1
Yes	1.046	0.686-1.593	0.835	1.180	0.737-1.889	0.491	1.172	0.767-1.791	0.464	1.396	0.862-2.261	0.175
FGFR1 amplification
Disomy/Low amplification	1			1			1			1
High amplification	2.001	1.099-3.644	0.023*	1.646	0.900-3.008	0.106	1.933	1.035-3.610	0.039*	1.544	0.823-2.896	0.176

Invasive depth I, tumors had invaded to the mucous layer or submucosa; II, to the muscularis propria; III, to or beyond the adventitia.

CI, confidence interval; HR, hazard ratio. ^*P<0.05 indicated that the 95% CI of HR was not including 1.