The impact of adjuvant endocrine therapy on reducing the risk of distant metastases in hormone-responsive breast cancer

Abstract

The primary goal of systemic adjuvant therapy for breast cancer is to control the risk of recurrence following surgery, thereby improving long-term survival. For many years, tamoxifen has served as the standard adjuvant endocrine therapy for postmenopausal women with hormone-sensitive breast cancer. The entry of the third-generation aromatase inhibitors (AIs) exemestane, anastrozole and letrozole as adjuvant therapy has introduced several different treatment options. Indirect comparisons suggest that appreciable differences may exist between the AIs in terms of early risk reduction, especially the risk for early distant metastases. Possible differences in efficacy may be related to differences in potency. Two ongoing trials directly comparing two AIs - the Femara versus Anastrozole Clinical Evaluation and MA.27 - may provide further information.