Polymorphisms of alcohol dehydrogenase 2 and aldehyde dehydrogenase 2 and colorectal cancer risk in Chinese males

Table 1 Background characteristics of male colorectal cancer patients and controls

	Controls		Patients		χ2MH	P
	No.	%	No.	%
Age (yr)
< 40	25	11.26	21	11.05	4.467	0.346
40-49	33	14.86	39	20.53
50-59	76	34.23	50	26.32
60-69	62	27.93	53	27.89
> 70	26	11.71	27	14.21
Total	222		190
Smoking status
Nonsmoker	87	39.19	67	35.26	3.794	0.150
Current smoker	122	54.95	102	53.68
Former smoker	13	5.86	21	11.05
Drinking status
Nondrinker	124	55.86	73	38.42	15.952	0.001
Current drinker	91	40.99	99	52.11
Former drinker	7	3.15	18	9.47
Kinds of alcoholic beverage
Hot wine	68	69.39	77	40.53	3.453	0.327
Beer	0	0	2	1.05
Wine	3	3.06	1	0.53
All kinds	27	27.55	37	31.62
Alcohol consumption (g/mo)
0-29	124	55.86	73	38.42	15.437	0.001
30-299	20	9.01	14	7.37
300-599	17	7.66	20	10.53
≥ 600	61	27.46	83	43.68

Table 2 Adjusted odds ratio (OR) and 95% confidence interval (CI) for colorectal cancer with reference to ALDH2 and ADH2 polymorphisms

	Controls n (%)	Cases n (%)	OR1 (95% CI)	OR2 (95% CI)
ALDH2 genotype
G/G	123 (55.41)	131 (68.95)	1.00	1.00
G/A	90 (40.54)	54 (28.42)	0.56 (0.37-0.86)	0.56 (0.37-0.86)
A/A	9 (4.05)	5 (2.63)	0.52 (0.15-1.76)	0.52 (0.17-1.60)
G/A + A/A	99 (44.59)	59 (31.05)	0.56 (0.37-0.86)	0.56 (0.37-0.84)
A/A + A/G	99 (44.59)	59 (31.05)	1.00	1.00
G/G	123 (55.41)	131 (68.95)	1.79 (1.19-2.68)	1.79 (1.19-2.69)
ADH2 genotype
A/A	93 (41.89)	102 (53.68)	1.00	1.00
A/G	109 (49.10)	73 (38.42)	0.61 (0.41-0.92)	0.62 (0.41-0.93)
G/G	20 (9.01)	15 (7.89)	0.68 (0.33-1.41)	0.68 (0.33-1.40)
A/G + G/G	129 (58.11)	88 (46.32)	0.62 (0.41-0.94)	0.63 (0.42-0.93)
G/G + G/A	129 (58.11)	88 (46.32)	1.00	1.00
A/A	93 (41.89)	102 (53.68)	1.61 (1.09-2.38)	1.60 (1.08-2.36)

¹Crude OR,

²OR was adjusted by age and smoking status.

Table 3 Adjusted OR and 95% CI for colorectal cancer with reference to alcohol drinking

	Controls	Cases	OR1 (CI)	OR2 (CI)
Alcohol drinking status
Non-drinker	124	73	1.00	1.00
Current drinker	91	99	1.85 (1.21-2.83)	1.84 (1.20 -2.82)
Former drinker	7	18	4.37 (1.62-12.17)	4.19 (1.64-0.71)
Current and former	98	107	2.03 (1.37-3.01)	2.04 (1.36-3.08)
Alcohol consumption (g/mo)
0-29	124	73	1.00	1.00
30-299	20	14	1.19 (0.53-2.65)	1.22 (0.58-2.58)
300-599	17	20	2.00 (0.93-4.30)	1.98 (0.96-4.09)
≥ 600	61	83	2.31 (1.46-3.68)	2.33 (1.47-3.71)
			P for trend = 0.0001

¹Crude OR,

²OR was adjusted for age and smoking status.

Table 4 Multivariant analysis of smoking, alcohol drinking, ALDH2 and ADH2 genotypes and risk of colorectal cancer

	OR1	95% CI	χ2	P
ALDH2	1.62	1.06-2.47	5.0035	0.0253
ADH2	1.73	1.15-2.58	7.0548	0.0079
Smokers	0.97	0.63-1.50	0.0138	0.9063
Alcohol drinkers	1.95	1.27-2.98	9.3884	0.0022

¹Logistic regression model included age (continuous), smoking (nonsmokers, current + former), alcohol drinking (nondrinkers, current + former drinkers), ALDH2 (A/A+A/G, G/G) and ADH2 genotype (G/G + G/A, A/A).

Table 5 Interaction between ALDH2 and ADH2 genotypes and OR for colorectal cancer

ALDH2	ADH2	Controls	Cases	OR1 (95% CI)
A/A + A/G	G/G + G/A	55	25	1.00
A/A + A/G	A/A	44	34	1.64 (0.85-3.18)
G/G	G/G + G/A	74	63	1.87 (1.05-3.35)
G/G	A/A	49	68	3.05 (1.67-5.57)

¹OR was adjusted for age and smoking in a logistic regression model.

Table 6 Interaction between alcohol drinking and polymorphisms of the ALDH2 and ADH2 genes, and the odds ratio (OR) for colorectal cancer

Genotypes	Drinker	Controls	Cases	OR1 (95% CI)
ALDH2
A/A + A/G	No	64	32	1.00
G/G	No	60	41	1.36 (0.76-2.43)
A/A + A/G	Yes	35	27	1.39 (0.69-2.81)
G/G	Yes	63	90	2.70 (1.57-4.66)
ADH2
G/G + G/A	No	65	34	1.00
A/A	No	59	39	1.27 (0.71-2.26)
G/G + G/A	Yes	64	54	1.65 (0.94-2.91)
A/A	Yes	34	63	3.44 (1.84-6.42)

¹OR was adjusted for age and smoking status.