Application of CfDNA Methylation Detection in Auxiliary Diagnosis of Breast Cancer

Inclusion Criteria for All the Participants: * With confirmed pathological diagnosis and molecular subtyping results * Ability to provide a written informed consent Exclusion Criteria for Cancer Arm Participants: * Patients with a history of or currently suffering from other malignancies * Pregnant or planning to become pregnant female patients * Patients who have received cancer treatment, including surgery, chemotherapy, radiotherapy, targeted therapy, and immunotherapy, before blood draw * Patients with a history of blood transfusion within the past month * Patients with a known history of allogeneic organ transplantation and allogeneic hematopoietic stem cell transplantation * Patients with persistent fever or undergoing anti-inflammatory treatment within 14 days before blood draw * Any other conditions that the researcher deems may make the patient unsuitable for inclusion in the study or may interfere with the completion of the study * Patients in poor physical condition who are not suitable for blood draw * Patients who cannot provide informed consent or refuse blood draw Exclusion Criteria for Benign Diseases Arm Participants: * History of malignancies * Current malignancies or precancerous lesions