Gene Expression Profiling of Colorectal Tumors and Normal Mucosa by Microarrays Meta-Analysis Using Prediction Analysis of Microarray, Artificial Neural Network, Classification, and Regression Trees

Table 1

Descriptive statistics of study samples.

Variables	Normal mucosa		Colorectal tumors		Logistic regression
	𝑛	%	𝑛	%	OR	𝑃 value
Gender (𝑛=759)
Female	10	48	331	45	1
Male	11	52	407	55	1.12	0.8
Age (𝑛=722)
≤60	17	81	240	33	1
>60	4	19	461	62	8.16	***
Race (𝑛 = 1,274)
European	14	16	321	27	1
Han	38	43	177	15	0.21	***
Australia	32	36	389	33	0.54	0.05
USA	4	5	299	25	3.26	*
Location of tissues (𝑛=272)
Proximal	5	11	32	14	1
Distal	42	89	193	86	0.72	0.52

OR: odds ratio; ^∗<0.05; ^∗∗∗<0.001. Proximal position: cecum, ascending colon, hepatic flexure, transverse colon, and splenic flexure. Distal position: descending colon, sigmoid colon, and rectum.