Changes of Cell-Free DNA Level in the Plasma of Breast Cancer Patients during Neoadjuvant Chemotherapy

Background and Aim: Preoperative chemotherapy is increasingly given to shrink breast tumors prior to surgery. Plasma cell-free DNA (cfDNA) is elevated in cancer patients and decreases in response to effective treatments. Thus, cfDNA is considered as potential tumor marker for monitoring chemotherapy. Methods: In the present study, we investigated whether the plasma DNA concentrations in patients with breast cancer are altered during the course of CMF, CAF neoadjuvant chemotherapy. Results: In CR, PR to chemotherapy patients, the cfDNA concentration decreases from week 1 of first cycle of treatment. In contrast, it increases after 2 weeks in patients who show NC, PD, without reference to chemotherapy method. Conclusion: This study shows the possibility of using cfDNA changes as a useful biomarker with other molecular changes for personalized medicine of breast cancer.