Risk-adapted adjuvant therapy of luminal early breast cancer in 2020

The present review summarizes recent original publications addressing the topic of risk-adapted adjuvant therapy in early breast cancer (EBC). As neoadjuvant therapy has become a standard for triple negative and HER2+ EBC, it focusses on luminal EBC.

Gene expression assays have become standard of care in luminal EBC, at least for patients with node negative disease. Two prospective randomized clinical trials, TAILORx (Oncotype DX) and MINDACT (MammaPrint) have presented additional analyses underlining the clinical utility of the tests. In times of COVID-19, immunohistochemically determined ER, PR, and Ki67 and early Ki67 response to endocrine therapy can be used to safely allocate patients for preoperative endocrine therapy and delay surgeries if resources are scarce. In patients with luminal high-risk disease, adding a CDK 4/6 inhibitor (abemaciclib) improves patient outcome already after short-term follow-up.

Determination of recurrence risk will remain important in luminal EBC for optimal therapy decisions. In the future, risk-adapted treatment concepts will include decision making for chemotherapy but also for endocrine-based approaches.