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

Table 1 Characteristics of studies of alcohol dehydrogenase-1B polymorphism and risk of esophageal cancer[15-27]

Study ID	Country, subjects	Cases	Controls	ADH1B
				Adjusted OR (95% CI)		Crude OR (95% CI)
				*1/*2 vs *2/*2	*1/*1 vs *2/*2	*1/*2 vs *2/*2	*1/*1 vs *2/*2
Yokoyama et al[15], 2006a	Japan, female	52	412	1.56 (0.56-4.35)	2.08 (0.76-5.56)	1.29 (0.7-2.4)	2.15 (0.81-5.7)
Boonyaphiphat et al[16], 2002a	Thailand	202	261	NAb	NA	1.15 (0.56-2.47)	2.01 (0.96-4.3)
Ding et al[17], 2009	China	221	191	1.21 (0.79-1.86)	2.78 (1.06-7.29)	1.30 (0.85-1.99)	2.42 (0.96-6.66)
Chao et al[18], 2000	China (Taiwan), alcoholics	88	327	NA	NA	1.61 (0.84-3.16)	4.85 (2.32-10.18)
Guo et al[19], 2008	China, male	80	480	2.89 (1.11-5.64)	NA	1.13 (0.66-1.93)	5.37 (2.45-11.46)
Li et al[20], 2008	Africa	220	241	-	-	-	-
Yang et al[21], 2005	Japan	165	494	1.57 (1.04-2.36)	0.62 (0.22-1.72)	2.08 (1.44-2.99)	1.12 (0.44-2.86)
Yang et al[22], 2007	China	191	198	1.89 (1.1-3.22)	1.91 (0.92-3.95)	1.35 (0.88-2.08)	1.92 (1.04-3.56)
Yokoyama et al[23], 2001a	Japan, alcoholic male	112	526	NA	NA	0.81 (0.46-1.43)	2.4 (1.48-3.88)
Yokoyama et al[24], 2002	Japan, male	234	634	NA	NA	1.16 (0.82-1.65)	5.73 (3.4-9.71)
Hori et al[25], 1997	Japan	94	130	1.7 (0.9-3.0)	6.2 (2.6-14.7)	1.33 (1.15-1.53)	6.2 (2.6-14.7)
Lee et al[26], 2008	China (Taiwan)	406	656	NA	NA	1.3 (0.97-1.73)	6.09 (4.07-9.23)
Hashibe et al[27], 2006	Europe	325	2550	NA	NA	0.64 (0.14-2.97)	0.85 (0.19-3.79)
Pooled results		2390	7100	1.60 (1.28-2.0)	2.17 (1.08-4.34)	1.32 (1.17-1.49)	2.91 (2.04-4.14)
P for heterogeneity				0.54	< 0.05	0.45	< 0.05

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

^bNA: Not available because not mentioned or calculated in the study. ADH1B: Alcohol dehydrogenase-1B; OR: Odds ratio; CI: Confidence interval.