Breast cancer is a common malignant tumor of the breast. About 30%-40% of breast cancer patients will experience recurrence or metastasis after breast cancer surgery. Breast cancer recurrence is generally related to the following three factors: 1. Breast cancer itself: because breast cancer is a highly suppressive malignant tumor, the different pathological types and biological characteristics of breast cancer determine a large difference in treatment response, some types of breast cancer have poor prognosis and have a higher probability of local recurrence or distant metastasis; 2. Patients’ own factors: for patients with poor physical condition For patients with poor physical condition and organ dysfunction, these factors will increase the possibility of breast cancer recurrence; psychological state is related to immunity, and stress will also cause weakness and decreased resistance, which will increase the risk of recurrence; 3, treatment: irregular treatment and incomplete treatment are also important factors leading to breast cancer recurrence. If there is no effective and comprehensive systemic treatment after surgery, these cancer cells will be hidden and become the root cause of breast cancer metastasis and recurrence in the future.