Abstract:Minimal residual disease(MRD) refers to the occult micro-metastasis or minimal residual lesions detected in tumor patients after targeted and radical treatment. Early and dynamic monitoring of MRD in breast cancer can assist clinical treatment decision-making and contribute to accurate diagnosis and treatment of breast cancer patients. With the development of new MRD detection technologies including circulating tumor cells and circulating tumor DNA, the role of MRD in breast cancer has been gradually verified, and it is expected to become a new risk stratification factor and prognostic indicator for breast cancer. This paper systematically reviews the research progress, opportunities and challenges in the field of MRD in breast cancer in recent years.