Features of synchronous and metachronous dual primary gastric and colorectal cancer

Table 2 Univariate and multivariate analysis for predictors of overall survival

Characteristics		Univariate		Multivariate
		HR (95%CI)	P value	HR (95%CI)	P value
Age	≤ 65	Reference
	> 65	1.8 (0.8-4.1)	0.162
Sex	Female	Reference
	Male	0.9 (0.4-2.0)	0.719
Location of gastric cancer	Lower	Reference
	Middle	1.9 (0.6-6.2)	0.262
	Upper	1.8 (0.7-4.1)	0.200
Stage of gastric cancer	0-II	Reference
	III-IV	6.7 (2.9-15.6)	< 0.001	10.0 (3.4-29.5)	< 0.0011
Resection of gastric cancer	No	Reference
	Yes	0.1 (0.1-0.3)	< 0.001	0.2 (0.1-0.6)	0.0021
Location of colorectal cancer	Right hemicolon	Reference
	Left hemicolon	1.1 (0.2-5.3)	0.909
	Sigmoid colon	1.1 (0.4-3.1)	0.882
	Rectum	0.9 (0.3-2.5)	0.863
Stage of colorectal cancer	0-II	Reference
	III-IV	1.1 (0.5-2.4)	0.831
Resection of colorectal cancer	No	Reference
	Yes	0.3 (0.1-0.6)	0.002	0.4 (0.1-1.5)	0.202
DPGCC	Metachronous	Reference
	Synchronous	3.0 (1.3-7.2)	0.013	6.8 (2.0-22.7)	0.0021

¹P value is statistically significant (P < 0.05).

95%CI: 95% confidence interval; DPGCC: Dual primary gastric and colorectal cancer; HR: Hazard ratio.