Hormone receptor positive breast cancer: state of the art

Purpose of review Hormone receptor (HR) positive breast cancer represents the vast majority of breast cancer cases. Treatment for these patients has been 5 years of endocrine therapy in the localized setting and endocrine therapy alone in the metastatic setting until progression of disease and switch to chemotherapy until quite recently. Recent findings The current article will review recent data on role of extended endocrine therapy with tamoxifen and aromatase inhibitors and adjuvant bisphosphonates in the localized disease setting. It will then review the role of targeted agents such as cyclin dependent kinases 4/6 inhibitors, two of which were FDA approved in 2017 in the metastatic setting and are now standard of care. Summary Landscape of HR positive breast cancer is changing with doubling of progression-free survival with drugs approved in the last 2 years. Although antiestrogen therapy remains the backbone of therapy, we are continuing to improve outcome for patients by changes and additions to this therapy.