This report will discuss a selection of key studies related to breast cancer discussed during the 2017 annual meeting of the American Society of Clinical Oncology. ASCO 2017 featured important new data generated with CDK4/6 inhibitors in patients with advanced breast cancer and included several abstracts considering the potential of PD-L1 inhibition for breast cancer. In addition to this, updates of several large phase III studies, including MARIANNE, ALLTO and APHINITY were presented. For a more complete overview of breast cancer news presented at ASCO 2017, we refer to the ASCO annual meeting website (