The specific survival time of patients with stage IV cancer varies widely after active treatment, and the five-year survival rate is highly disease-related, at about 3% to 10%. Cancer is a common malignant disease that can be caused by a variety of factors such as gene mutation, environment and heredity. Stage IV patients mostly represent the emergence of distant metastasis, such as lung metastasis, liver metastasis, bone metastasis and so on. During this period, the disease is more complicated and the patient’s physical condition is poorer, and there is no chance of surgical resection of the lesions. The treatments for stage IV patients are mostly non-surgical therapies, such as radiotherapy, targeted therapy, symptomatic therapy, and so on. The purpose of treatment is to prolong the survival period and improve the quality of life of patients. There are some differences in five-year survival rate, such as about 5% for non-small cell lung cancer: about 3% for small cell lung cancer, etc. The cure rate can be slightly increased if the patients are in good physical condition and have a high degree of tolerance to the treatment.