title: Cytochrome P450 1B1 gene polymorphisms and postmenopausal endometrial cancer risk.
abstract: Estrogen unopposed by progestins is a key factor in endometrial cancer etiology. Cytochrome P450 1B1 (CYP1B1), responsible for the 4-hydroxylation of estrogen, may be important in endometrial carcinogenesis, either as a regulator of estrogen availability or as a producer of potentially genotoxic estrogen metabolites. We investigated the association of CYP1B1 genotype and endometrial cancer risk in a population-based case-control study of postmenopausal Swedish women. We used the Expectation-Maximization algorithm to estimate the haplotype frequencies in the population and calculated odds ratios and 95% confidence intervals from conditional logistic regression models. In stratified analysis, we investigated the possible effects of CYP1B1 genotype on endometrial cancer risk in subgroups defined primarily by menopausal hormone use and also by body mass index, smoking, use of combined oral contraceptives, and family history. We genotyped 689 cases and 1,549 controls for the CYP1B1 single nucleotide polymorphisms m2, m3, and m4 and estimated the haplotype frequencies among controls to 0.086, 0.291, 0.452, and 0.169 for the CYP1B1*1, CYP1B1*2, CYP1B1*3, and CYP1B1*4 alleles, respectively. We found no evidence for an overall association between CYP1B1 genotype and endometrial cancer risk, nor was there any clear indication of gene-environment interaction.
authors.affiliation: Division of Molecular Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden. tove.rylander-rudqvist@imm.ki.se
authors.forename: Tove
authors.initials: T
authors.lastname: Rylander-Rudqvist
authors.forename: Sara
authors.initials: S
authors.lastname: Wedrén
authors.forename: Gudrun
authors.initials: G
authors.lastname: Jonasdottir
authors.forename: Susanne
authors.initials: S
authors.lastname: Ahlberg
authors.forename: Elisabete
authors.initials: E
authors.lastname: Weiderpass
authors.forename: Ingemar
authors.initials: I
authors.lastname: Persson
authors.forename: Magnus
authors.initials: M
authors.lastname: Ingelman-Sundberg
mesh_terms: D000368:Aged; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics*; D016022:Case-Control Studies; D065633:Cytochrome P-450 CYP1B1; D016889:Endometrial Neoplasms / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D005838:Genotype; D006239:Haplotypes / Q000235:genetics; D020249:Hormone Replacement Therapy; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D017698:Postmenopause; D012306:Risk; D013223:Statistics as Topic; D013548:Sweden
chemical_list: D001189:Aryl Hydrocarbon Hydroxylases; C585496:CYP1B1 protein, human; D065633:Cytochrome P-450 CYP1B1