The main symptoms of mid-stage breast cancer include: 1) painless lumps in the affected breasts, which are often found unintentionally due to the lack of self-conscious symptoms; 2) nipple overflow, with different overflow colors representing different diseases. At the same time, it is accompanied by abnormalities of nipple and areola, such as nipple atrophy and nipple eczema-like cancer; 3. Breast shape change, nipple offset to the direction of cancer, and if the cancer cells block lymphatic ducts, it will appear orange peel-like change; 4. Breast pain occurs in some patients; 5. Lymphatic metastasis of breast cancer is reflected in the enlargement of lymph nodes of axilla on the same side.