Assessing ctDNA Dynamics in HR-Positive, HER2-Negative Advanced Breast Cancer

Dr. Jason Mouabbi and Dr. Seth Wander discuss the evolving role of circulating tumor DNA dynamics as a potential tool for evaluating treatment response in HR-positive, HER2-negative advanced breast cancer. Dr. Mouabbi highlights emerging evidence exploring the relationship between ctDNA clearance and clinical outcomes across multiple tumor types, emphasizing the growing interest in molecular markers of response. Dr. Wander reviews data evaluating changes in ESR1 mutation levels following biomarker-guided treatment adaptation, including how monitoring variant allele fraction may provide insights into tumor evolution and endocrine resistance. The experts discuss how changes in ctDNA patterns may help clinicians better understand treatment effects beyond traditional imaging assessments. The conversation highlights ongoing research into the role of dynamic molecular monitoring and its potential to further personalize treatment strategies for patients with HR-positive, HER2-negative advanced breast cancer.