The risks and benefits of hormonal replacement therapy in healthy women and in breast cancer survivors

For many years hormonal replacement therapy (HRT) has been considered to offer not only effective relief of climacteric symptoms but also a reduction in the risk of osteoporosis and cardiovascular disease, plus a possible prevention of cognitive decline. Randomised trials of HRT in women with preexisting coronary heart disease have not confirmed, however, cardiovascular benefits of HRT and have even suggested increased cardiac risk associated with this management. Numerous retrospective studies demonstrated that the risk of breast cancer is higher in HRT-users and is related to therapy duration. More recent studies suggested that breast cancer risk increases further if oestrogen is coupled with progestogen. On the other hand, some data show that breast cancers diagnosed in women during HRT administration may be less aggressive. Typically, tumours in these patients are smaller and better differentiated. HRT also increases the relative risk of endometrial cancer, particularly if oestrogen alone is administered. Currently, the indications for HRT in healthy subjects should include only reduction of menopausal symptoms and prevention of osteoporosis. The use of HRT in breast cancer survivors is controversial, and until the results from prospective randomised trials are available, cannot be recommended in this group as a standard care.