Progression of endocrine therapies for breast cancer: where are we headed?

Abstract

Endocrine therapy remains a key part of the management of patients with hormone receptor-positive breast cancer. Tamoxifen has been the gold standard for 25 years and remains a very effective treatment. The third generation aromatase inhibitors (anastrozole, letrozole and exemestane), however, have shown slightly greater efficacy in both metastatic and early breast cancer with a different side-effect profile and no major toxicities identified to date. In premenopausal women, the role of ovarian suppression is being assessed in addition to other therapies. Experimental studies suggest synergy between endocrine therapy and signal transduction inhibitors, and these are being explored in clinical trials. A key question for all forms of endocrine therapy remains optimal duration. Evidence is emerging to suggest that, for some women, treatment should be continued for many years and perhaps lifelong.

Keywords::

• breast cancer
• endocrine
• therapy

Acknowledgment

Monica Arnedos would like to thank the Cridlan Fund for their support in the preparation of this manuscript.

Financial & competing interests disclosure

Ian Smith has received honoraria from AstraZeneca, Novartis and Pfizer over the last few years. He also held a consultancy agreement with Novartis which was discontinued 2 years ago. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.