Table 4. Multivariable cox proportional hazards analyses of clinicopathologic factors associated with death from esophageal cancer, stratified by SEER summary stage.

Factor	Localized(n=11,548)				Regional(n=15,431)				Distant(n=17,020)
	HR	P	95% CI		HR	P	95% CI		HR	P	95% CI
Sex
Female	Referent
Male		NS	0.9	1.2	1.1	0.02	1.02	1.2		NS	1.0	1.2
Tumor grade
I	Referent
II	1.3	0.002	1.1	1.6	1.2	0.008	1.1	1.4	1.1	0.5	0.9	1.2
III	1.7	<0.0001	1.4	2.0	1.4	<0.0001	1.3	1.7	1.2	0.01	1.0	1.5
Undifferentiated	1.8	0.001	1.3	2.6	1.3	0.1	1.0	1.6	1.2	0.3	0.9	1.5
Age at diagnosis, years
<=65	Referent
>65	1.3	<0.0001	1.2	1.5	1.2	<0.0001	1.1	1.3	1.16	<0.0001	1.1	1.2
Ethnic group
NHW	Referent
Black	1.1	0.2	1.0	1.3	1.2	<0.0001	1.1	1.3	1.2	<0.0001	1.1	1.3
HW	1.1	0.3	0.9	1.3	1.0	0.8	0.9	1.1	1.1	0.1	1.0	1.2
Asian	0.8	0.08	0.7	1.0	1.1	0.3	0.9	1.2	1.0	0.5	0.8	1.1
Tumor histology
EAC	Referent
ESCC	1.16	0.002	1.1	1.3		NS	0.9	1.0	0.87	0.001	0.8	0.9
Lymph node status
Negative	Referent
Positive	1.1	<0.0001	1.1	1.2	1.4	<0.0001	1.2	1.3	1.14	<0.0001	1.1	1.2
Cancer-directed surgery
Not performed	Referent
Performed	0.4	<0.0001	0.3	0.5	0.6	<0.0001	0.6	0.7	0.55	<0.0001	0.5	0.6
Tumor size (cm)	1.02	<0.0001	1.02	1.03	1.02	<0.0001	1.02	1.03	1.01	<0.0001	1.004	1.02
Tumor location within esophagus
Upper	Referent
Middle		NS	0.9	1.2		NS	0.9	1.1	1.1	0.03	1.02	1.3
Lower		NS	0.8	1.0		NS	0.9	1.1	1.0	0.4	0.9	1.2
Year of diagnosis
1998-2005	Referent
2006-2013	0.89	0.02	0.8	0.98	0.88	<0.0001	0.8	0.9	0.9	0.008	0.9	0.98

HR, hazard ratio; CI, confidence interval; NS, not significant; EAC, esophageal adenocarcinoma; ESCC, esophageal squamous cell carcinoma.