CDK4/6 Inhibition in HR-Positive Breast Cancer: Evolving Standards in Early and Metastatic Care

This segment outlines how CDK4/6 inhibitors have reshaped therapeutic expectations across early-stage and metastatic HR-positive, HER2-negative breast cancer. The panel highlights that in the metastatic setting, agents such as ribociclib, abemaciclib, and palbociclib rapidly became foundational after demonstrating significant improvements in progression-free survival when combined with aromatase inhibitors. Ribociclib carries a category 1 guideline recommendation based on overall survival gains observed in the MONALEESA program. The discussion also reviews the expanding adjuvant role of CDK4/6 inhibitors, noting positive findings from the monarchE and NATALEE trials, which support their use for patients with high-risk or genomically defined risk features. The experts emphasize how these data have broadened the therapeutic continuum by pairing endocrine sensitivity with targeted cell cycle blockade, ultimately strengthening long-term disease control strategies for diverse risk groups within HR-positive disease.