-765G > C COX-2 polymorphism may be a susceptibility marker for gastric adenocarcinoma in patients with atrophy or intestinal metaplasia

Table 1 Characteristics of the participants: age, gender and type and stage of lesions

	Control	Gastricadenocarcinoma	Atrophy or intestinalmetaplasia
	n = 210	n = 73	n = 37
Age
(mean ± SD)	49.5 ± 18.0	54.2 ± 11.3	60.7 ± 10.9
Male Gender n (%)	135 (64)	36 (49)	15 (40)
Atrophy n (%)	Na	Na	3 (8)
Complete IM n (%)	Na	Na	4 (11)
Incomplete IM n (%)	Na	Na	30 (81)

Na: Not applicable; Atrophic chronic gastritis without intestinal metaplasia.

Table 2 Genotype distribution of COX-2 -765G > C polymorphism

Genotype	Controls(n = 210)		Atrophy or intestinalmetaplasia(n = 37)		Gastricadenocarcinoma(n = 73)
	n (%)	P1	n (%)	P2	n (%)
GG	130 (62)	0.197	27 (73)	0.018	36 (49)
GC	67 (32)	0.357	9 (24)	0.046	32 (44)
CC	13 (6)	0.398	1 (3)	0.339	5 (7)
C carrier	80 (38)	0.197	10 (27)	0.018	37 (51)

¹vs Atrophy or intestinal metaplasia group (chi-square test); ²vs Gastric adenocarcinoma group (chi-square test).

Table 3 Frequency distributions and Odds Ratio for risk of atrophy and intestinal metaplasia or gastric adenocarcinoma in -765 C carriers

Pathology	Genotype n (%)		OR (95% CI)		OR2(95% Cl)
	GG	C carrier
Controls	130 (62)	80 (38)	1.00 (Reference)	1.00 (Reference)1
Atrophy or intestinal metaplasia	27 (73)	10 (27)	0.60 (0.28-1.31)	0.95 (0.91-0.99)1	1.00 (Reference)
Gastric adenocarcinoma	36 (49)	37 (51)	1.67 (0.98-2.86)	1.45 (0.84-2.64)1	2.67 (1.03-6.93)

¹ OR adjusted for age and gender in a multivariate logistic regression analysis;

² OR adjusted for age and gender in a multivariate logistic regression analysis for the progression of atrophy or intestinal metaplasia into gastric cancer.

Table 4 C allele frequency and C carriers distribution in different countries

Country	n1	C allelefrequency (%)	C carrierdistribution (%)
America
USA[39]	228	21	37
USA (African American)[39]	100	32	52
Europe
Portugal (our study)	210	22	38
Italy[44]	864	28	50
UK[34]	454 (males)	14	25
Poland[43]	547	17	31
Australia
Australia[45]	168	17	31
Asia
Singapore[36]	1177	5	9
Japan[35]	241	2	5
China[18]	1270	2	4

¹ in control populations of the mentioned studies.