Clinical Applications for Liquid Biopsy Assessment of Minimal Residual Disease in Breast Cancer

Purpose of Review: We review current techniques and applications for minimal residual disease (MRD) detection in patients without detectable metastasis using circulating tumor cells (CTC) and circulating tumor DNA (ctDNA) in breast cancer. We discuss the evidence for MRD detection in predicting patient outcomes and how these assays could be used to guide treatment decisions. Recent Findings: Current research has demonstrated that MRD detection through liquid biopsy techniques predicts patient outcomes. Increasingly, studies are showing MRD detection can be used to develop personalized treatment strategies based on the presence or absence of MRD and the detection of molecular targets. Summary: MRD detection through liquid biopsy-based assays is associated with the risk of disease recurrence. Additionally, MRD assays may be useful in guiding personalized treatment approaches. Future research will focus on the clinical utility of MRD assays to further validate their role in predicting outcomes and guiding treatment decisions, including escalation or de-escalation treatment strategies for patients.