Reducing the risk of distant metastases in breast cancer patients: role of aromatase inhibitors.

Breast cancer continues to be one of the most prominent causes of cancer death among women worldwide. Mortality in breast cancer is most commonly caused by the occurrence of distant metastases. Thus, treatments that reduce the risk of distant metastases are likely to improve survival. The third-generation aromatase inhibitors (AIs), including anastrozole, letrozole, and exemestane, have been investigated as alternatives to tamoxifen for the adjuvant treatment of early, endocrine-responsive breast cancer. Results from several large trials have established the superior efficacy of the AIs over tamoxifen in reducing the risk of recurrences when used as upfront, switch, and extended adjuvant therapy. Here, we review recent updated results obtained with AIs as adjuvant therapy, in terms of reducing the risk of distant metastases.