Abstract 2857: SULT1A1 gene copy number variations and functional polymorphism in relation to breast cancer risk

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC Sulfotransferase (SULT) 1A1 enzyme plays an important role in the detoxification of environmental and dietary procarcinogens as well as the regulation of a number of steroid hormones, including estrogens. SULT1A1 gene is located in the short arm of chromosome 16, which has been shown to contain many repetitive sequences and to be highly duplicated. It has been suggested that SULT1A1 gene displays variations in copy number. In our previous study, a common functional polymorphism rs9282861 (213Arg>His) in SULT1A1 was associated with an elevated risk of breast cancer in postmenopausal Caucasian women. In this study, we evaluated copy number variations and functional polymorphism rs9282861 of SULT1A1 gene in relation to breast cancer risk. Included in the study were 1,989 breast cancer cases and 1,918 controls from the Shanghai Breast Cancer Study II, a population-based, case-control study conducted among Chinese women. SULT1A1 gene copy number was determined by real-time PCR assays and genotyping was conducted using TaqMan assays. One to five copies of the SULT1A1 were observed in our population. Approximately 22.6% of these women were found to have more than 2-copy of the SULT1A1 gene and 1.7% of these women were found to have 1-copy of the gene. No woman was found to have null copy of SULT1A1 gene. No overall association of the SULT1A1 gene copy number variations with breast cancer risk was observed. We found that the A allele (213His) of rs9282861 was associated with a reduced risk of breast cancer risk. Women carrying GA/AA genotypes had an OR of 0.81 (95%CI=0.68-0.97) compared to women carrying GG genotype. The inverse association was constraint in pre-menopausal women with OR of 0.68 (95%CI=0.53-0.87) for women carrying GA/AA genotypes compared to those carrying GG genotype. There is no interaction between SULT1A1 gene copy number variations and polymorphism 213Arg>His in relation to breast cancer risk. Our data suggest that functional 213Arg>His polymorphism of SULT1A1 gene, not SULT1A1 gene copy number change, may play a role in the etiology of breast cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2857.