Defining High-Risk HR-Positive Early Breast Cancer

Erica Mayer, MD, and Kelly McCann, MD, outline how clinicians define high-risk hormone receptor–positive, HER2-negative early breast cancer in contemporary practice. The discussion reviews how traditional anatomic features such as nodal status intersect with biologic factors including tumor grade, Ki-67, and genomic assays. Trial eligibility criteria from monarchE and NATALEE are placed in the context of real-world risk assessment, highlighting which patients may warrant escalation beyond endocrine therapy alone. The faculty also address the importance of introducing complex adjuvant treatment plans in a thoughtful, patient-centered manner to avoid overwhelming individuals at diagnosis. This foundational discussion establishes the clinical framework used to identify appropriate candidates for adjuvant CDK4/6 inhibitors.