Emerging Innovative Therapeutic Approaches Leveraging Cyclin-Dependent Kinase Inhibitors to Treat Advanced Breast Cancer.

Estrogen receptor-positive (ER+) tumors represent the most common form of breast cancer. Although endocrine therapy (ET) results in benefit for the majority of these patients, disease progression invariably occurs. The discovery of the relation between cyclin-dependent kinases (CDKs) and the ER pathways is one of the major advances in unveiling mechanisms of resistance to ET. In this article we review the role of CDK4/6 inhibitors in ER + breast cancer patients.