title: Cytochrome P450 1B1 and catechol-O-methyltransferase genetic polymorphisms and breast cancer risk in Chinese women: results from the shanghai breast cancer study and a meta-analysis.
abstract: Cytochrome P450 1B1 (CYP1B1) and catechol-O-methyltransferase (COMT) are important estrogen-metabolizing enzymes and, thus, genetic polymorphisms of these enzymes may affect breast cancer risk. A population-based case-control study was conducted to assess the association of breast cancer risk with CYP1B1 and COMT polymorphisms. A meta-analysis was done to summarize the findings from this and previous studies. Included in this study were 1,135 incident breast cancer cases diagnosed from August 1996 through March 1998 among female residents of Shanghai and 1,235 randomly selected, age frequency-matched controls from the same general population. The common alleles of the CYP1B1 gene were Arg (79.97%) in codon 48, Ala (80.53%) in codon 119, and Leu (86.57%) in codon 432. The Val allele accounted for 72.46% of the total alleles identified in codon 108/158 of the COMT gene. No overall associations of breast cancer risk were found with any of the single nucleotide polymorphisms described above. This finding was supported by a meta-analysis of all previous published studies. No gene-gene interactions were observed between CYP1B1 and COMT genotypes. The associations of breast cancer risk with factors related to endogenous estrogen exposure, such as years of menstruation and body mass index, were not significantly modified by the CYP1B1 and COMT genotypes. We observed, however, that women who carried one copy of the variant allele in CYP1B1 codons 48 or 119 were less likely to have estrogen receptor-positive breast cancer than those who carried two copies of the corresponding wild-type alleles. The results from this study were consistent with those from most previous studies, indicating no major associations of breast cancer risk with CYP1B1 and COMT polymorphisms.
authors.affiliation: Department of Medicine, Vanderbilt-Ingram Cancer Center, Center for Health Service Research, Vanderbilt University School of Medicine, Nashville, TN, USA.
authors.forename: Wanqing
authors.initials: W
authors.lastname: Wen
authors.forename: Qiuyin
authors.initials: Q
authors.lastname: Cai
authors.forename: Xiao-Ou
authors.initials: XO
authors.lastname: Shu
authors.forename: Jia-Rong
authors.initials: JR
authors.lastname: Cheng
authors.forename: Fritz
authors.initials: F
authors.lastname: Parl
authors.forename: Larry
authors.initials: L
authors.lastname: Pierce
authors.forename: Yu-Tang
authors.initials: YT
authors.lastname: Gao
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
mesh_terms: D000328:Adult; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics*; D044466:Asian People / Q000235:genetics; D001943:Breast Neoplasms / Q000453:epidemiology / Q000208:ethnology / Q000235:genetics*; D016022:Case-Control Studies; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D065633:Cytochrome P-450 CYP1B1; D005260:Female; D005838:Genotype; D006801:Humans; D008875:Middle Aged; D011110:Polymorphism, Genetic; D011960:Receptors, Estrogen; D012307:Risk Factors
chemical_list: D011960:Receptors, Estrogen; D001189:Aryl Hydrocarbon Hydroxylases; C585496:CYP1B1 protein, human; D065633:Cytochrome P-450 CYP1B1; D002394:Catechol O-Methyltransferase