Refining Risk Assessment for Adjuvant CDK4/6 Inhibitors beyond Trial Inclusion Criteria: Integrating Recurrence Score and Endocrine Responsiveness according to ADAPT

Among 4365 WSG-ADAPT-HR+/HER2- patients, N0-1 cases receiving ET after ET-response and meeting NATALEE but not monarchE criteria had only slightly inferior outcomes vs. the low-risk group. Assuming a hazard ratio of 0.7 for a ribociclib effect in NATALEE, an absolute benefit of approximately 2% fewer dDFS events after 5 years could be expected in this group based on the WSG-ADAPT-HR+/HER2- experience. ET-response evaluation can refine prognosis to better inform shared decision-making in this intermediate-risk group.