Role of Exemestane in the Treatment of Estrogen-Receptor-Positive Breast Cancer: A Narrative Review of Recent Evidence

Introduction Breast cancer (BC) is the most common type of cancer diagnosed among women worldwide with an estimated 2.3 million new cases every year. Almost two-thirds of all patients with BC have estrogen receptor-positive (ER+) tumors. In this review, the clinical evidence of exemestane in different treatment settings in ER+ BC is presented and summarized. Search strategy A search strategy with the keywords "breast cancer [MeSH Terms]" AND "exemestane [Title/Abstract]" was devised and a search was performed in PubMed. Results The efficacy of exemestane in different treatment settings has been established by numerous clinical studies. Exemestane is recommended as an adjuvant treatment in postmenopausal women previously treated with tamoxifen in trials comparing 5 years of tamoxifen with 2-3 years of tamoxifen combined with 2-3 years of exemestane, which proved that treatment with exemestane provided better survival outcomes. Similarly, exemestane could be considered as a safe treatment option for neoadjuvant treatment, prevention of chemotherapy, and treatment of advanced BC either alone or in combination with other targeted therapy drugs in both pre- and postmenopausal women. Conclusion Exemestane could be considered as a reasonable therapeutic option in the treatment of ER+ BC at any stage in pre- and postmenopausal women.