To prevent tumor recurrence and metastasis, we need to pay attention to two aspects: First, regular review. Although tumor patients have recovered after surgery and radiotherapy, the root cause of tumor patients’ treatment failure is that tumor will recur and metastasize within a certain period of time. Regular follow-up and regular examination can detect recurrence and metastasis. Taking gastric cancer as an example, regular examination, regular hematological examination, such as tumor markers, blood routine, stool routine, stool occult blood, etc., regular gastroscopy, liver ultrasound examination and chest CT examination are very important parts to prevent recurrence and metastasis; secondly, follow-up, which requires medical specialists or nurses, within the time period of patient’s confirmed treatment, such as Second, follow-up visits require medical specialists or nurses to contact patients or their families for regular telephone follow-ups every 3 months for 5 years, or patients to visit the specialist clinic for follow-up visits to understand the patient’s recent status, such as physical status, diet, and any discomfort. Through regular follow-up visits, we are able to objectively understand the general condition of the patient.