Sentinel lymph node metastasis in the left breast requires comprehensive treatment such as surgery, radiotherapy and targeted therapy according to the severity of the disease and the patient’s physical fitness to improve the prognosis of the disease. 1. Surgical treatment: if the tumor foci are more limited, the spread is more limited, and the patient’s physical condition is better, surgery can be chosen to remove the foci and clear the lymph nodes to improve the symptoms, and it is also recommended to assist radiotherapy after surgery. 2. Radiotherapy and targeted therapy: for patients who cannot tolerate surgery and patients whose lesions cannot be removed, radiotherapy and targeted therapy can be chosen to improve the prognosis of the disease, chemotherapy drugs and targeted therapy drugs need to be standardized under the guidance of doctors, and it is recommended to consult a doctor for the occurrence of adverse reactions, and the drugs are prohibited for those who are allergic to them. Therefore, it is recommended to consult a doctor as soon as possible after the occurrence of anterior lymph node metastasis in the left breast, and actively cooperate with the doctor to receive standardized treatment.