Hormonal treatment of breast cancer: new developments

Hormonal treatment of breast cancer has been revisited during the last few years. New drugs have been introduced and shown to improve patient outcome, both with regard to efficacy and side effects. Historical aspects and newer developments are presented. New drugs such as second- and third-generation aromatase inhibitors and new antiestrogens have recently been introduced in the clinic or are in late development. Promising results have been obtained with new endocrine agents in third- and fourth-line treatment. Future research directions are given and the endocrine treatment of breast cancer is placed in perspective of future therapeutic options using 'biological treatment' to influence the regulation of cell growth and cell proliferation.