Aromatase inhibitors in the breast cancer therapy and their potential using in the prevention setting.

Long term exposure to estradiol is associated with an increased risk of breast cancer. Aromatase inhibitors, suppressing tumour and plasma estrogen levels by blocking conversion of testosteron to estrogen, have been proven to provide the most effective endocrine therapy in metastatic and adjuvant setting in postmenopausal women. Questions remains about the long term side effects and safety profile of aromatase inhibitors. The effectiveness and safety of aromatase inhibitors therapy in premenopausal breast cancer patients is unknown, this needs to be further investigated. Although tamoxifen represents the gold standard for prevention therapy at present, results of ongoing studies may indicate a role of aromatase inhibitors in prevention of breast cancer (Tab. 2, Ref. 22).