Table 2. Univariate and multivariate COX analysis of OS in training set.

Characteristics		Univariate analysis	Multivariate analysis
		p-value	HR	95% CI	p-value
Race		0.028			0.041
	White		Reference
	Black		1.15	1.03–1.28	0.016
	Others		0.97	0.84–1.12	0.670
Gender		<0.001			0.019
	Male		Reference
	Female		0.91	0.83–0.98	0.019
Primary site		<0.001	NA
	Head
	Body
	Tail
	Others
Grade		<0.001			<0.001
	High differentiated		Reference
	Low differentiated		1.59	1.40–1.80	<0.001
	Unknown		1.18	1.05–1.31	0.004
Pathological types		<0.001			<0.001
	Ductal adenocarcinoma		Reference
	Non-ductal adenocarcinoma		0.40	0.36-0.45	<0.001
AJCC		<0.001			<0.001
	I		Reference
	II		3.05	2.23–3.96	<0.001
	III		3.10	2.30–4.18	<0.001
	IV		4.63	3.53–6.07	<0.001
Surgery		<0.001			<0.001
	No		Reference
	Yes		0.43	0.38-0.50	<0.001