Effects of estrogen deprivation due to breast cancer treatment

Breast cancer is one of the main life-threatening diseases that a woman may have to face during her lifetime. The increasing incidence of breast neoplasia reported over the last few decades has led to widespread screening of women resulting in early diagnosis. One common but challenging question for most doctors, after the surgical excision of the lesion, is determination of the ideal adjuvant therapy for their patients for the achievement of maximum life expectancy with the best quality of life. Since the beginning of the last century, the knowledge that breast cancer arises from hormone-responsive tissues has long made use of hormone-blocking agents in the beneficial treatment of breast neoplasia. The discovery of new molecules with endocrine actions has rendered the use of adjuvant therapy in a tailor-made pattern too complicated, as these agents have a different mode of action, different adverse effects and probably different indications. The aim of the present review is to clarify these issues, analyzing the mechanism of action of available drugs and their actions on specific areas of uncertainty: cognitive function, cardiovascular system, urogenital tract, bone metabolism, weight gain, hot flushes and premature menopause. Regarding the efficacy of adjuvant therapy, there has been particular focus on the multiple hormonal-induced consequences of each regimen in order to provide the clinician with the available data for choosing the ideal therapy for the patient.