This study will be divided into two stages. The first stage will complete the screening, identification, model construction and target verification of polygene methylation markers in the blood of breast cancer patients. The second stage will explore its application in monitoring prognosis and recurrence after radical mastectomy.~The first stage (inclusion detection period) : By detecting the DNA methylation characteristics of breast cancer (including tissue and plasma) and non-breast cancer samples (breast tissue/plasma of healthy people, and plasma samples of patients with benign breast lesions), screening, identification and verification of plasma ctDNA polygene methylation markers that can distinguish the differences between breast cancer and non-breast cancer samples are carried out.~The second stage (postoperative monitoring and evaluation) : The enrolled group was the initially treated patients who planned to undergo radical mastectomy. Plasma methylation markers were detected before surgery at baseline, and dynamic monitoring of plasma ctDNA polygene methylation detection, related tumor markers and imaging examinations were performed 3 weeks after surgery (or before the start of chemotherapy) and regular follow-up review (once every 3 months for 2 years). To explore the clinical application value of ctDNA methylation status in postoperative breast cancer surgery and follow-up monitoring.
This study screened and identified effective methylation markers in breast cancer, established a detection system for early screening and early diagnosis, and provided a research basis for the embryonic form of non-invasive breast cancer early screening products in later incubation. Then, the plasma ctDNA polygene methylation test was performed for early and middle stage breast cancer patients who were to receive radical surgery for initial treatment, and the predictive effect of postoperative plasma ctDNA methylation status on postoperative prognosis of breast cancer was discussed. In addition, the application value of dynamic monitoring of ctDNA methylation in plasma for postoperative recurrence risk monitoring was explored through regular postoperative follow-up of stage I-III breast cancer patients undergoing radical surgery.