Current status and perspective of ctDNA-based MRD testing in breast cancer: a systematic review

Treatment strategies for breast cancer have become increasingly complex over the years, requiring a deep understanding of disease pathology and the individualization of treatments on the basis of biomarkers. Circulating tumor DNA (ctDNA) enables non-invasive evaluation of the entire tumor, and its potential is being explored for treatment development. Numerous studies have evaluated ctDNA in various breast cancer subtypes during postoperative follow-up or after neoadjuvant chemotherapy, consistently showing that ctDNA positivity is associated with a higher risk of recurrence. Clinical trials evaluating therapeutic interventions on the basis of ctDNA status are also underway. Moving forward, the development of more sensitive assays and appropriate treatment strategies will be required. As the clinical application of ctDNA advances, the individualization of breast cancer treatment is expected to be further refined.