Tamoxifen: From breast cancer therapy to the design of a postmenopausal prevention maintenance therapy

There are now exciting opportunities for developing a new prevention maintenance therapy for postmeno-pausal women. These strategies hold the promise of retarding the development of osteoporosis, coronary heart disease, and breast and endometrial cancer. An understanding of the molecular events involved in the target-site-specific effects of estrogen through a novel ERβ system or the selective activation of genes by antiestrogen through novel response elements provides a basis for new drug discovery in the future. However, for the present, the well-documented clinical effects of estrogen coupled with the expanding data base with tamoxifen have laid the foundation for the current clinical trials with raloxifene. Clinical studies with a large population of postmenopausal women will soon establish the efficacy of the drug to treat and prevent osteoporosis, and ancillary studies will confirm its actions in preventing breast cancer and coronary heart disease. Raloxifene is the first of a series of new agents that holds the potential to revolutionize the approach to disease prevention in the majority of postmenopausal women.