Drugs for the gynecologist to prescribe in the prevention of breast cancer: Current status and future trends

Tamoxifen was approved for breast cancer prevention in October 1998. Thus, for the first time, we as gynecologists are being asked to prescribe this drug to healthy women. In the past each one of us has cared for women with breast cancer who have been treated with tamoxifen by oncologists or breast surgeons for the malignancy. Effects of tamoxifen on the uterus resulting in carcinomas, hyperplasia, and polyps are well known, Furthermore, tamoxifen has estrogenic properties in the venous system, increasing the incidence of deep vein thrombosis and pulmonary emboli. A new SERM (selective estrogen receptor modulator), raloxifene, has been approved for prevention and treatment of osteoporosis in postmenopausal women. It does not have stimulatory effects on the endometrium; however, it is estrogenic in the venous system. Preclinical data, as well as the breast cancer incidence reported in studies of the skeleton, seem to indicate that its effects in the breast are similar to those of tamoxifen. This article reviews tamoxifen and the new SERM, raloxifene, in an attempt to help gynecologists better understand each compound and what data are currently known, what we hope to learn from future studies, and what currently makes sense for clinical practice.