There are benign and malignant tumors. Benign tumors grow slowly, have envelope and clear boundary, and usually will not recur after surgical removal. However, malignant tumor is different, it grows fast and has strong ability to destroy body tissues, and can even metastasize to other parts of the body through lymph, blood vessels and body cavity. Of course, not all malignant tumors will recur, and there are 6 other determining factors to look at: the nature of the tumor itself, the long duration of the disease, incomplete removal, the patient’s own poor condition, unchanged cancer body, and bad living habits. Although we have done a lot of preventive work, the tumor may appear again, what we need to do at this time is: 1. Don’t be afraid, don’t give up, and build up confidence to continue treatment. 2.Visit the medical oncology department, if it is an outside patient, you need to bring the previous medical records. 3.If possible, it is better to do biopsy to clarify the pathology. 4.Perfect the whole body examination to clarify the metastasis site and scope. Treatment principles: 1. Consider chemotherapy for visceral metastases, rapid disease progression, failure of endocrine therapy or estrogen/progesterone receptor negativity. 2. Consider radiotherapy for bone metastases with symptoms. 3.Patients with slowly progressing disease and estrogen/progesterone receptor (+) bone, skin and soft tissue metastases (excluding visceral metastases) can consider endocrine therapy. 4.Aromatase inhibitors are preferred for patients who fail adjuvant tamoxifen therapy. 5.Progestin (megestrol acetate/methacholine) or fulvestrant may be chosen if aromatase inhibitor therapy fails. 6.Patients who have not been treated with anti-estrogen in the past or have failed adjuvant therapy for more than 1 year can still try tamoxifen or toremifene.