CYP2E1 Rsa I polymorphism impacts on risk of colorectal cancer association with smoking and alcohol drinking

Table 1 Background characteristics of colorectal cancer cases and their controls

	Controls n (%)	Colorectal cancer n (%)	Colon cancer n (%)	Rectal cancer n (%)
All of the subjects	439 (100.0)	315 (100.0)	105 (100.0)	210 (100.0)
Gender
Males	223 (50.8)	190 (60.3)	65 (61.9)	125 (59.5)
Females	216 (49.2)	125 (39.7)	40 (38.1)	85 (40.5)
χ2MH (P)		6.70 (0.010)	4.19 (0.041)	4.34 (0.037)
Age (yr)
< 40	42 (9.6)	44 (14.0)	14 (13.3)	30 (14.3)
40-49	75 (17.1)	54 (17.1)	15 (14.3)	39 (18.6)
50-59	150 (34.2)	88 (27.9)	30 (28.6)	58 (27.6)
60-69	131 (29.8)	85 (29.0)	26 (24.8)	59 (28.1)
> 70	41 (9.3)	44 (14.0)	20 (19.1)	24 (11.4)
χ2MH (P)		9.37 (0.053)	10.23 (0.037)	5.69 (0.224)
Mean age ± SD	55.7 ± 11.0	55.3 ± 12.7	56.4 ± 13.4	54.7 ± 12.3
P (t test)		0.6172	0.6325	0.3159
Smoking status
Nonsmoker	284 (64.7)	176 (55.9)	61 (58.1)	115 (54.8)
Courrent and former	155 (35.3)	139 (44.1)	44 (41.9)	95 (45.2)
χ2MH (P)		5.99 (0.014)	1.59 (0.208)	5.91 (0.015)
Alcohol status
Nondrinker	327 (74.5)	176 (55.9)	65 (61.9)	120 (57.1)
Current and former	112 (25.5)	139 (44.1)	50 (38.1)	90 (42.9)
χ2MH (P)		28.58 (0.000)	14.19 (0.000)	19.90 (0.000)
CYP 2E1 genotypes1
c1/c1	266 (61.4)	185 (59.1)	63 (60.6)	122 (58.4)
c1/c2	154 (35.6)	106 (33.9)	35 (33.7)	71 (34.0)
c2/c2	13 (3.0)	22 (7.0)	6 (5.8)	16 (7.7)
χ2MH (P)		6.58 (0.037)	1.91 (0.385)	7.07 (0.029)

¹Six controls and two cases were excluded because of unknown CYP2E1 genotype.