Methylation status of COX-2 in blood leukocyte DNA and risk of gastric cancer in a high-risk Chinese population

BMC Cancer

Table 2 The temporal trends of COX-2 methylation levels during GC development

	n	Methylation proportion	P ^a
	n	Median % (interquartile range)	P ^a
Total pre-GC and post-GC samples
Pre-GC	74	2.5(1.5–4.4)
Post-GC	95	2.3(1.2–3.9)
P ^b		0.32
Temporal trend
5–10 years pre-GC	32	1.9(1.4–4.0)	0.53
1–4 years pre-GC	42	3.0(2.0–4.5)	0.01
GC diag. year	46	2.2(1.1–2.8)	Ref.
1–4 years post-GC	21	1.9(1.4–2.9)	0.80
5–10 years post-GC	28	2.8(1.8–4.9)	0.06
P _trend ^c		0.32

^aMann-Whitney Test/Wilcoxon Test
^b Unconditional logistic regression analysis, adjusted for age, gender, smoking, drinking and H. pylori infection status
^c Unconditional logistic regression analysis

ISSN: 1471-2407