CYP1A1, GSTM1, GSTT1 and NQO1 polymorphisms and colorectal adenomas in Japanese men

Table 4 Associations between genetic polymorphisms and colorectal adenomas with stratification by smoking category

Genotype	< 20 pack-years		≥20 pack-years		Interaction (P)
	n1	OR (95%CI)2	n1	OR (95%CI)2
CYP1A1*2A
03	59/207	1.00 (referent)	115/181	2.22 (1.52-3.24)	0.45
≥ 1	100/346	1.05 (0.73-1.53)	181/318	1.95 (1.37-2.76)
CYP1A1*2C
03	106/329	1.00 (referent)	175/282	1.90 (1.41-2.56)	0.59
≥ 1	53/224	0.76 (0.52-1.11)	121/217	1.65 (1.20-2.27)
GSTM1
Non-null	69/264	1.00 (referent)	131/242	1.99 (1.41-2.82)	0.96
Null	90/289	1.19 (0.83-1.71)	165/257	2.35 (1.68-3.29)
GSTT1
Non-null	89/268	1.00 (referent)	169/284	1.74 (1.27-2.38)	0.26
Null	70/285	0.74 (0.52-1.06)	127/215	1.69 (1.21-2.36)
GSTM1 + GSTT1
04	39/134	1.00 (referent)	79/139	1.87 (1.18-2.96)	0.63
1	80/264	1.03 (0.67-1.61)	142/248	1.91 (1.26-2.91)
2 (both null)	40/155	0.89 (0.54-1.48)	75/112	2.14 (1.34-3.43)
NQO1 C609T
CC	52/221	1.00 (referent)	109/191	2.23 (1.51-3.29)	0.46
CT + TT	107/332	1.35 (0.93-1.97)	187/308	2.51 (1.75-3.60)

¹Number of cases/controls;

²Adjusted for age, hospital, rank in the Self-Defense Forces, body mass index, cigarette smoking, alcohol use, leisure-time physical activity and parental history of colorectal cancer;

³Number of variant alleles;

⁴Number of null genotypes.