CATECHOL-O-METHYLTRANSFERASE AND BREAST-CANCER RISK

Recent studies suggest that a polymorphism in catechol-O-methyltransfe rase (COMT) is associated with increased risk of breast cancer. Methyl ation by COMT is the principal pathway for inactivation of catechol es trogens, which are hypothesized to participate in estrogen-induced car cinogenesis. We examined the association of COMT genotype and breast c ancer risk in a population-based, case-control study of invasive breas t cancer in North Carolina. The study population consisted of 654 case s and 642 controls, with approximately equal numbers of African-Americ an and white women and women under the age of 50 and aged 50 or over. Contrary to previous reports, we did not observe an association betwee n one or more copies of the low activity COMT allele (COMT-L) and brea st cancer risk. Multivariate relative risks (RRs) were 0.8 (95% confid ence interval: 0.6-1.1) for COMT-HL and 0.8 (0.6-1.1) for COMT-LL, com pared with the COMT-HH genotype, RRs for COMT did not differ among Afr ican-American and white women and we did not observe strong modificati on of RR estimates by menopausal status, body mass index, physical act ivity or other covariates, Our results suggest that COMT genotype is n ot related to breast cancer risk.