Raloxifene and its role in breast cancer prevention

Abstract

Raloxifene (Evista, Eli Lilly), a selective estrogen receptor modulator (SERM) and ligand for the estrogen receptor (ER), competes with endogenous estrogen for ER binding. Raloxifene is approved for the prevention and treatment of osteoporosis, and shows promise as a breast cancer prevention drug. Raloxifene may be a preferred agent over tamoxifen due to its side-effect profile; in particular, it does not stimulate the endometrium and is not associated with endometrial cancer. The mechanisms for the differential tissue effects of raloxifene compared with other SERMs are not completely understood; the roles of ERalpha and -beta, classic and alternative signaling pathways, and drug conformation are discussed in this review. The utility of raloxifene will depend on the outcome of trials that are now underway, as well as acceptance by high-risk women and their healthcare practitioners.