N-Acetyltransferase 2 genetic polymorphisms and risk of colorectal cancer

Table 1 Characteristics of the patients in both groups n (%)

Parameters	Patients	Control	P
Age (yr, ± DP)	61.9 (13.6)	62.0 (13.4)	0.96a
≤ 50	30 (20.4)	31 (14.6)	0.196b
> 5	17 (79.5)	181 (85.4)
Gender
Male	71 (48.3)	85 (40.1)	0.15b
Female	76 (51.7)	127 (59.9)
Tumor site
Colon	90 (61.2)
Rectum	57 (38.8)
Stage
I	23 (15.6)
II	65 (44.2)
III	39 (26.5)
IV	20 (13.6)

^at test;

^bχ² test.

Table 2 Distribution of N-acetyltransferase 2 polymorphism and the risk of cancer

Genetic polymorphism NAT2a	Cancer, n (%)	Control, n (%)	P	OR (95% CI)
All	147	212
Mx/Mx	88 (59.8)	110 (51.9)	0.19	1
W/Mx	44 (30.0)	83 (39.1)		0.66 (0.42-1.05)
W/W	15 (10.2)	19 (8.9)		0.99 (0.47-2.05)
Slow	88 (59.8)	110 (51.9)	0.17	1.38 (0-2.12)
Fast	59 (40.1)	102 (48.1)
Female	76	127
Mx/Mx	42 (55.2)	58 (45.6)	0.07	1
W/Mx	23 (30.2)	58 (45.6)		0.55 (0.29-1.02)
W/W	11 (14.4)	11 (8.6)		1.38 (0.55-3.48)
Slow	42 (55.2)	58 (45.6)	0.24	1.47 (0.83-2.60)
Fast	34 (44.7)	69 (54.3)
Male	71	85
Mx/Mx	46 (64.8)	52 (61.1)	0.67	1
W/Mx	21 (29.5)	25 (29.4)		0.95 (0.47-1.92)
W/W	4 (5.6)	8 (9.4)		0.57 (0.16-2.00)
Slow	46 (64.7)	52 (61.1)	0.76	0.86 (0.45-1.65)
Fast	25 (35.2)	33 (38.9)

^aHomozygous individuals with genotype W/W, and heterozygote W/Mx, are grouped into fast acetylation phenotype, while homozygous Mx/Mx are grouped in slow acetylators. The percentages of data are in parentheses. NAT2: N-acetyltransferase 2; OR: Odds ratio; 95% CI: Confidence interval.

Table 3 Comparison between meat intake and risk of of cancer in rapid acetylator patients n (%)

	Cancer	Control	P	OR	Lower95% CI/upper
All	59	102
High meat intake1	44 (74.5)	60 (58.8)	0.06	2.05	1.01/4.16
Low meat intake2	15 (25.5)	42 (41.2)

¹More than 3 time per week;

²Less than 3 times a week. OR: Odds ratio; 95% CI: Confidence interval.

Table 4 Correlation between genotypes and risk for cancer in smokers or ex-smokers

Genetic polymorphism	Cancer, n (%)	Control, n (%)	P	OR (95% CI)
NAT2a
All	65	87
Mx/Mx	40 (61.5)	39 (44.8)	0.09	1
W/Mx	22 (33.8)	39 (44.8)		1.82 (0.92-3.60)
W/W	3 (4.6)	9 (10.3)		3.08 (0.77-12.22)
Slow	40 (61.5)	39 (44.8)	0.06	1.97 (1.02-3.79)
Fast	25 (38.5)	48 (61.0)

^aHomozygous individuals with genotype W/W, and heterozygote W/Mx, are grouped into fast acetylation phenotype, while homozygous Mx/Mx are grouped in slow acetylators. NAT2: N-acetyltransferase 2; OR: Odds ratio; 95% CI: Confidence interval.