What is anterior lymph node: it is the first group of lymph nodes through which breast cancer must metastasize, and only after this group of lymph nodes metastasizes can it metastasize to other lymph nodes. In traditional radical breast cancer surgery or modified radical surgery, axillary lymph node dissection is performed. Afterwards, many patients have different degrees of edema, limitation of movement, local sensory impairment and numbness in the affected upper limbs, which may affect the function and rest of the upper limbs in severe cases, and the discomfort may be unimaginable for normal people. Of course, many patients without lymph node metastasis also suffer from the complication of upper limb edema, which is an innocent disease. If the anterior lymph nodes are negative, axillary lymph node dissection is not necessary. This reduces the surgical trauma and complications of surgery. It greatly improves the quality of survival of patients with early stage breast cancer. If axillary lymph node metastasis occurs some time after surgery, additional axillary lymph node dissection does not affect the survival of the patient.