Stage III should be subclassified into Stage IIIA and IIIB in the American Joint Committee on Cancer (8th Edition) staging system for pancreatic cancer

Table 2 Univariable analyses for overall survival in stage III pancreatic cancer patients

Characteristics	T(1-3)N2 (n = 1526)			T4N(0-1) (n = 138)			T4N2 (n = 80)
	HR	95%CI	aP	HR	95%CI	bP	HR	95%CI	cP
Age
18-59	Reference			Reference			Reference
60-79	1.083	0.947-1.239	0.244	1.357	0.801-2.298	0.256	1.924	1.005-3.682	0.048
> 80	1.343	1.040-1.734	0.024	2.223	0.847-5.838	0.105	1.307	0.285-5.998	0.731
Race
White	Reference			Reference			Reference
Black	1.068	0.858-1.328	0.558	1.155	0.573-2.328	0.688	0.885	0.316-2.476	0.816
Others	1.058	0.825-1.357	0.656	0.835	0.354-1.970	0.681	1.678	0.575-4.895	0.344
Sex
Male	Reference			Reference			Reference
Female	1.016	0.896-1.152	0.806	1.003	0.645-1.561	0.989	0.437	0.222-0.859	0.016
Grade
I	Reference			Reference			Reference
II	2.045	1.549-2.701	0.000	1.240	0.594-2.586	0.567	4.708	1.375-16.119	0.014
III	2.578	1.952-3.407	0.000	1.379	0.646-2.944	0.406	9.385	2.593-33.972	0.001
IV	3.788	1.973-7.272	0.000	-	-	-	14.118	1.734-114.943	0.013
Unknown	2.005	1.381-2.911	0.000	0.484	0.146-1.597	0.233	3.357	0.698-16.153	0.131
Marital status
Single	Reference			Reference			Reference
Married	0.882	0.772-1.007	0.064	0.560	0.336-0.935	0.027	1.566	0.779-3.150	0.208
Unknown	1.001	0.649-1.544	0.995	3.268	0.710-15.034	0.128	0.196	0.019-2.007	0.170
Primary site
Head of pancreas	Reference			Reference			Reference
Other parts of pancreas	1.222	1.039-1.437	0.015	0.872	0.537-1.416	0.579	1.219	0.553-2.688	0.624
Histology
Adenomas and adenocarcinomas	Reference			Reference			Reference
Ductal and lobular neoplasms	1.089	0.960-1.236	0.184	1.166	0.730-1.864	0.52	1.617	0.746-3.506	0.224
Others	1.017	0.782-1.322	0.902	0.964	0.504-1.844	0.913	1.712	0.729-4.020	0.217