Refining Adjuvant Strategy in HR-Positive Breast Cancer: Integrating monarchE and NATALEE Evidence

This segment examines how long-term data from the monarchE and NATALEE trials are shaping the selection of adjuvant CDK4/6 inhibition for early-stage HR-positive, HER2-negative breast cancer. The experts interpret the 7-year monarchE update as confirming a sustained overall survival advantage with abemaciclib in patients with high-risk features, reinforcing its role for node-positive and clinically aggressive disease. They also highlight outcomes from the 5-year NATALEE trial, in which ribociclib demonstrated a meaningful benefit across stages II to III disease, including selected node-negative or genomically intermediate groups that still carry a biologic risk. When considered together, both trials support a more individualized approach that takes into account nodal status, genomic signatures, tumor grade, and patient age to determine who may benefit from therapy intensification. The panel notes that overlapping but distinct eligibility criteria across studies allow clinicians to better tailor CDK4/6 inhibitor choice based on risk profiles and treatment goals