Breast cancer is one of the most common malignant tumors in women. Breast cancer can be divided into four stages according to the size of the tumor, the presence or absence of lymph node metastasis, and the presence or absence of distant metastasis. 1. Stage I: it means the lump is completely located in the breast tissue, the diameter is not more than two centimeters, there is no adhesion with the skin, and there is no metastasis in the axillary lymph nodes. 2. Stage II: It is a tumor with a diameter of two to five centimeters, with or without adhesion to the skin, with a certain degree of mobility, and with enlarged lymph nodes in the axilla, but without a tendency to fuse. 3. Stage III: It is the presence of internal breast lymph node metastasis. 4. Stage IV: the tumor widely invades the breast skin, forms satellite nodes or is fixed with the chest wall, and there is extensive lymph node metastasis or distant metastasis, including bone, lung and brain. Patients with breast cancer should go to the hospital in time to confirm the diagnosis, and under the guidance of doctors, carry out standardized treatment.