If the cancer cannot find the primary lesion but has multiple lymph node metastases, chemotherapy, radiotherapy or targeted therapy should be adopted according to the specific conditions of the patient. 1. Chemotherapy: When the primary lesion of cancer cannot be found, chemotherapy drugs can be used to treat the whole body, which can inhibit the growth and reproduction of tumor cells, but also have certain damage to normal tissues of the human body, so it is important to observe whether the patient has obvious gastrointestinal adverse reactions and determine whether there is bone marrow suppression and other conditions. 2. Radiotherapy: when the cancer cannot find the primary lesion, local treatment can be carried out according to the metastatic lesion, and local radioactive treatment can be carried out, but it is easy to have related complications, such as radioactive treatment of lung metastatic tumor may induce radioactive pneumonia. 3. Targeted therapy: genetic testing is needed before targeted therapy, usually patients have gene mutation problems, and need to choose reasonable drug treatment plan under the guidance of doctors. For patients with metastases who cannot find the primary lesion, it is recommended to consult the oncology department of regular hospitals.