How we treat HR-positive, HER2-negative early breast cancer.

The present goal of therapy for early HR+/HER2- breast cancer (BC) is to optimize disease-free survival (DFS) and overall survival (OS) rates with the currently available therapies while avoiding any relevant long-term sequalae. Local therapies have evolved toward less aggressive techniques (i.e. breast-preserving surgery, sentinel lymph node biopsy and intraoperative radiotherapy), which significantly reduce the long-term sequalae observed with more radical treatments. Endocrine therapy (ET) is still the cornerstone of adjuvant treatment because it significantly reduces BC relapse and mortality. Adjuvant chemotherapy is today recommended only for a particular subset of patients with a high risk of recurrence with ET alone, identified through genomic assays, age and/or disease stage. Bisphosphonates reduce the risk of bone metastasis and produce a slight although statistically significant improvement in survival in postmenopausal women. The CDK 4/6 inhibitor abemaciclib has been recently approved by the US FDA for patients at high risk of relapse.