Personalized circulating tumor DNA (ctDNA) testing, intervention, and temporal dynamics in ER+-HER2- early-stage breast cancer (LEADER)

Arielle Medford, MD, discusses findings from the LEADER study, which evaluates the clinical utility of circulating tumor DNA (ctDNA)–based molecular residual disease (MRD) testing in early-stage breast cancer. The talk explains how highly sensitive ctDNA assays can detect minimal residual disease months before radiographic or clinical recurrence, offering a potential window for earlier intervention. Dr. Medford outlines the study design, patient population, and longitudinal monitoring approach used in LEADER, with a focus on hormone receptor–positive, HER2-negative disease. She also reviews emerging evidence linking ctDNA positivity to recurrence risk and treatment outcomes and addresses how MRD testing could be integrated into routine clinical workflows. Overall, the presentation highlights the role of ctDNA-guided strategies in advancing personalized cancer care, improving risk stratification, and informing future clinical trials aimed at preventing breast cancer recurrence.