Cytochrome p450-17alpha Polymorphism and Risk of Breast Cancer

摘要

Previous studies indicate that circulating estradiol is significantly elevated in breast cancer patients compared to controls in high and low risk populations. A variation in enzyme activity, i.e., the polymorphism of genes encoding the enzymes responsible for the metabolism and binding of estrogen may be related to an altered risk of breast cancer. The cytochrome P45O17a, an enzyme involved in estrogen biosynthesis has shown the most potential in the etiology of breast cancer. In this study we investigated whether a polymorphism of the CYP 17 gene, involved in the biosynthesis of estrogen, is associated with an altered risk of breast cancer among a population-based sample of women (400 cases and 400 controls) participating in the Long Island Breast Cancer Study Project. We also explored whether the effects of reproductive risk factors and exposure to exogenous estrogen or estrogen-like substances are modified by the CYP 17 polymorphism. In addition we are investigating the relation between urinary estrogen metabolites and the CYP 17 polymorphism. Since this polymorphism is prevalent in the population, it may potentially contribute to a high population attributable risk. Unfortunately, at this time, due to the politically sensitive nature of the parent Long Island project (P.1. Marilie Gammon) we are not permitted to release the actual results of this.