Aromatase inhibitors in postmenopausal breast cancer patients

Aromatase inhibitors (AIs) have greatly enriched the treatment of hormone receptor-positive breast cancer in postmenopausal patients. Before the introduction of the well-tolerated third-generation AIs, tamoxifen was the mainstay of endocrine therapy for hormone receptor-positive breast cancer. Many clinical trials have shown the superiority of AIs compared with tamoxifen in adjuvant breast cancer treatment, as well as their benefit in metastatic breast cancer. NCCN guidelines recommendations for their use are based on the evidence provided by these clinical trials. This discussion reviews the evidence supporting the current guidelines for use of AI therapy in the treatment of hormone receptor-positive postmenopausal breast cancer patients.