The evidence that alcohol consumption increases a woman's chances of getting
breast cancer is now more persuasive. Higher blood concentrations of
organochlorine compounds were not associated with increased risk of
breast cancer in recent studies. The relationship of exogenous
estrogen use to
breast cancer risk is now clarified: current users of both
oral contraceptives and
hormone replacement therapy experience a slightly elevated risk that dissipates after cessation of use. Alcohol consumption and
hormone replacement therapy are both associated with slightly increased
breast cancer risk, but the overall health benefits of
hormone replacement therapy and low levels of alcohol consumption appear to outweigh the risks in the general population. These circumstances underscore the complex decisions facing women and the need to consider individual risk factor profiles. For the genes BRCA1 and BRCA2, more data are needed to understand the risks associated with specific mutations, optimal implementation of genetic testing, and prevention and early detection strategies for women who have positive test results. Interesting leads in identifying women at increased risk for
breast cancer have been generated via the study of genetic polymorphisms. The results of
tamoxifen in the
Breast Cancer Prevention Trial have made the possibility of
chemoprevention for
breast cancer a reality.
Raloxifene, another
antiestrogen, has emerged as a potential chemopreventive agent. Its efficacy in reducing
breast cancer risk will be compared with that of
tamoxifen in a randomized trial.