title: Polymorphisms of alcohol dehydrogenase 2 and aldehyde dehydrogenase 2 and colorectal cancer risk in Chinese males.
abstract: OBJECTIVE
  To evaluate the relationship between drinking and polymorphisms of alcohol dehydrogenase 2 (ADH2) and/or aldehyde dehydrogenase 2 (ALDH2) for risk of colorectal cancer (CRC) in Chinese males.
  
  
  METHODS
  A case-control study was conducted in 190 cases and 223 population-based controls. ADH2 Arg47His (G-A) and ALDH2 Glu487Lys (G-A) genotypes were identified by PCR and denaturing high-performance liquid chromatography (DHPLC). Information on smoking and drinking was collected and odds ratio (OR) was estimated.
  
  
  RESULTS
  The ADH2 A/A and ALDH2 G/G genotypes showed moderately increased CRC risk. The age- and smoking-adjusted OR for ADH2 A/A relative to G/A and G/G was 1.60 (95% CI=1.08-2.36), and the adjusted OR for ALDH2 G/G relative to G/A and A/A was 1.79 (95% CI=1.19-2.69). Significant interactions between ADH2, ALDH2 and drinking were observed. As compared to the subjects with ADH2 G and ALDH2 A alleles, those with ADH2 A/A and ALDH2 G/G genotypes had a significantly increased OR (3.05, 95% CI= 1.67-5.57). The OR for CRC among drinkers with the ADH2 A/A genotype was increased to 3.44 (95% CI= 1.84-6.42) compared with non-drinkers with the ADH2 G allele. The OR for CRC among drinkers with the ALDH2 G/G genotype was also increased to 2.70 (95% CI= 1.57-4.66) compared with non-drinkers with the ALDH2 A allele.
  
  
  CONCLUSIONS
  Polymorphisms of the ADH2 and ALDH2 genes are significantly associated with CRC risk. There are also significant gene-gene and gene-environment interactions between drinking and ADH2 and ALDH2 polymorphisms regarding CRC risk in Chinese males.
authors.affiliation: Division of Epidemiology, Jiangsu Provincial Institute of Cancer Research, 42 Baiziting, Nanjing, China. gaocm888@126.com
authors.forename: Chang-Ming
authors.initials: CM
authors.lastname: Gao
authors.forename: Toshiro
authors.initials: T
authors.lastname: Takezaki
authors.forename: Jian-Zhong
authors.initials: JZ
authors.lastname: Wu
authors.forename: Xiao-Mei
authors.initials: XM
authors.lastname: Zhang
authors.forename: Hai-Xia
authors.initials: HX
authors.lastname: Cao
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Ding
authors.forename: Yan-Ting
authors.initials: YT
authors.lastname: Liu
authors.forename: Su-Ping
authors.initials: SP
authors.lastname: Li
authors.forename: Jia
authors.initials: J
authors.lastname: Cao
authors.forename: Keitaro
authors.initials: K
authors.lastname: Matsuo
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Hamajima
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tajima