Physiologic effects of steroid hormones and postmenopausal hormone replacement on the female breast and breast cancer risk.

Most data demonstrate that breast cancer is hormonally influenced. For the woman with no history of breast cancer, the benefits of HRT may outweigh the risks. Although it remains the standard of care to discourage hormone use in patients who have had breast cancer, future studies may result in a change of this standard. There needs to be more research into these complex hormonal interactions so that we will have a better understanding of the true risks and benefits when we attempt to advise our patients regarding the best treatment regimens for them.