Adjuvant treatment of breast cancer in postmenopausal women: role of exemestane

Adjuvant hormonal therapy significantly reduces the risk of recurrence and death following surgery for estrogen receptor (ER)-positive early breast cancer. Previously, the gold standard hormonal therapy was tamoxifen, a selective modulator of the ER. However, large clinical trials conducted over the past decade have defined the efficacy of an alternative class of hormonal agent, namely the third-generation aromatase inhibitors (AIs): exemestane, letrozole, and anastrozole. On the basis of the pivotal International Exemestane Study (IES), exemestane, a steroidal third-generation AI, was licensed for the adjuvant treatment of postmenopausal women with ER-positive early breast cancer following 2-3 years of tamoxifen to complete a total of 5 years of adjuvant hormonal therapy. Here, we consider recent data to emerge primarily from the IES and Tamoxifen Exemestane Adjuvant Multicenter trials and consider their implications for the role of exemestane in the adjuvant treatment of breast cancer.