[Action of SERM and SAS (tibolone) on breast tissue].

SERMs are developed in HRT in order to provide the beneficial effects of estradiol on bone and the cardiovascular system. SERMs are antiestrogens and their properties depend upon the pharmacological class they belong to. Tibolone is a progestin with mixed properties. Our studies on breast cells in vitro demonstrated that it behaves as a progestin in these cells. The clinical data obtained with these various therapies on breast are presented.