Adjuvant endocrine therapy

Endocrine therapy remains a cornerstone of systemic therapy for breast cancer even though it was first introduced more than a century ago. In the past three decades a large number of randomized trials involving several tens of thousands of patients have been performed to determine the role of endocrine therapy in the adjuvant setting. The results of these studies indicate that hormonal therapy should be considered the standard adjuvant systemic treatment for the majority of patients with invasive breast cancer irrespective of age, menopausal status or tumour stage. This chapter aims to describe the ‘state of the art’ relative to the use of adjuvant endocrine therapy with special focus on a number of salient issues, including: (i) the role of ovarian ablation and luteinising hormone releasing hormone (LHRH) analogues among pre-menopausal patients; (ii) optimal duration of tamoxifen; (iii) adjuvant therapy with third-generation, selective aromatase inhibitors; (iv) predictive biomarkers; (v) side-effects; (vi) combination endocrine therapy; (vii) future development of endocrine therapy.