When subclavian lymph nodes are found to be enlarged two years after breast cancer surgery, subclavian lymph node metastasis should be considered firstly and corresponding examination should be done. If metastasis is diagnosed, surgery should be the first choice, and radiotherapy or targeted drug therapy should be carried out after surgery as appropriate. If subclavian lymph nodes are found to be enlarged two years after breast cancer surgery, further examination should be done, which may include CT of neck or chest, magnetic resonance imaging (MRI), and lymph node puncture biopsy to confirm the nature of the enlarged lymph nodes. If subclavian lymph node metastasis without distant metastasis is diagnosed, the metastasis should first be removed by surgery. After surgery, radiotherapy or targeted drug therapy can be decided depending on the situation. Radiotherapy means irradiating the lymph nodes with a certain amount of radiation, and the lymph nodes will shrink or even disappear after radiotherapy. Targeted drugs are mainly for HER-2 gene amplification, which can be divided into two main categories, the first category is monoclonal antibody class (the most commonly used), such as trastuzumab, patuximab, etc.; the second category is small molecule tyrosinase inhibitor class, commonly used lapatinib, pyrrolitinib and so on. In addition, immunohistochemical testing of HER-2 gene should be done before targeted therapy. It is recommended to go to a regular hospital for examination and use medication under the guidance of a professional doctor.