Tamoxifen for breast cancer prevention

Tamoxifen is of proven efficacy in the treatment of breast cancer. New data indicate that it might be able to reduce the occurrence of receptor positive breast cancer when taken as a preventative. However trade-offs for this reduction are an increased incidence of endometrial carcinomas and thromboembolic events. Therefore the use of tamoxifen as preventative ought to be restricted to clinical studies or a well defined high risk situation. Whether raloxifen is superior to tamoxifen remains to be shown.