The treatment of cancer recurrence depends on whether it is local recurrence and whether there is distant metastasis. For example, if papillary thyroid cancer has been treated with lymph node dissection in the neck, and the enlarged lymph nodes in the neck appear again later, it is considered to be a recurrence, and if the patient’s physical condition allows, he can have lymph node dissection in the neck again, that is, surgery, and of course, it can also be treated with nuclear iodine-131. In case of recurrence of malignant tumors in other areas, depending on the patient’s physical condition, if surgery is not possible, it can be combined with local radiotherapy, which can control recurrence, and there are also systemic chemotherapy modalities that can be used. If the cancer recurrence means the disease progresses, it may be better to choose some other treatment modalities, like targeted therapy.