Relationship between genetic polymorphisms of ALDH2 and ADH1B and esophageal cancer risk: A meta-analysis

Table 2 Characteristics of studies of aldehyde dehydrogenase-2 polymorphism and risk of esophageal cancer[15-26,28-33]

Study ID	Country, subjects	Cases	Controls	ALDH2
				Adjusted OR (95% CI)		Crude OR (95% CI)
				*1/*2 vs *1/*1	*2/*2 vs *1/*1	*1/*2 vs *1/*1	*2/*2 vs *1/*1
Yokoyama et al[15], 2006a	Japan, female	52	412	1.01 (0.54-1.87)	1.49 (0.47-4.78)	1.13 (0.62-2.06)	1.56 (0.5-4.88)
Boonyaphiphat et al[16], 2002a	Thailand	202	261	1.57 (0.89-2.76)	0.52 (0.05-5.33)	1.33 (0.82-2.17)	0.22 (0.03-1.87)
Ding et al[17], 2009	China, male	221	191	1.71 (1.1-2.66)	4.84 (2.25-10.61)	1.7 (1.08-2.68)	5.69 (2.51-12.18)
Chao et al[18], 2000	China (Taiwan), alcoholics	88	327	NAb	NA	3.54 (2.16-5.8)	1.33 (0.28-6.4)
Guo et al[19], 2008	China, male	80	480	NA	NA	1.5 (0.93-2.42)	0.1 (0.01-1.67)
Li et al[20], 2008a	Africa	237	268	NA	NA	1.24 (0.62-2.46)	2.73 (0.79-10.69)
Yang et al[21], 2005	Japan	165	494	6.43 (4.02-10.3)	1.92 (0.23-15.7)	2.08 (1.44-2.99)	1.12 (0.44-2.86)
Yang et al[22], 2007	China	191	198	1.67 (1.02-2.72)	0.26 (0.06-1.09)	1.35 (0.88-2.08)	1.92 (1.04-3.56)
Yokoyama et al[23], 2001	Japan, alcoholic male	112	526	13.50 (8.06-22.6)	-	11.8 (7.36-18.94)	Excludedc
Yokoyama et al[24], 2002	Japan, male	234	634	7.46 (4.71-11.81)	7.83 (1.33-46.08)	3.66 (2.62-5.1)	0.25 (0.06-1.07)
Hori et al[25], 1997	Japan	93	171	4.4 (2.5-7.7)	0.9 (0.2-3.6)	4.35 (2.42-7.83)	0.93 (0.24-3.55)
Lee et al[26], 2008	China (Taiwan)	406	656	NA	NA	2.88 (2.19-3.77)	0.91 (0.48-1.72)
Cai et al[28], 2006	China	205	394	0.76 (0.5-1.16)	1.72 (0.85-3.48)	0.69 (0.47-0.99)	2.25 (1.2-4.22)
Ding et al[29], 2002	China	98	235	NA	NA	0.91 (0.56-1.47)	0.24 (0.05-1.07)
Itoga et al[30], 2004	Japan, male	74	241	NA	NA	2.28 (2.19-3.77)	0.95 (0.2-4.57)
Matsuo et al[31], 2001	Japan	102	241	3.72 (1.88-7.36)	0.8 (0.09-6.88)	2.48 (1.52-4.03)	0.19 (0.025-3.52)
Yokoyama et al[32], 1996	Japan, male	29	28	NA	-	9.2 (4.22-20.07)	Excludedc
Yokoyama et al[33], 2006	Japan, alcoholic male	42	273	NA	NA	13.83 (6.16-31)	Excludedc
Pooled results		2631	6030	2.06 (1.09-3.89)	1.31 (0.52-3.34)	2.52 (1.76-3.61)	0.76 (0.42-1.40)
P for heterogeneity				< 0.001	< 0.001	< 0.001	< 0.001

^aThe genotype frequencies among the controls differed significantly from the Hardy-Weinberg equilibrium (P < 0.05);

^bNA: Not available;

^cNo studies were included because there were no cases and controls with ALDH2*2/*2. ALDH2: Aldehyde dehydrogenase-2; OR: Odds ratio; CI: Confidence interval.