1, primary prevention: stop the common causes of cancer, such as physical factors, chemical factors and biological factors. For example, by eating garlic, reduce the incidence of gastric cancer; Reduce the incidence of liver cancer by avoiding eating moldy food;

2. Secondary prevention: In order to find, diagnose and treat early, patients and medical staff need to cooperate accurately at this time. First, early detection: understand the high-risk factors in the environment (such as smoking, alcoholism, hepatitis infection, etc. ); Second, early diagnosis: if patients find abnormal symptoms, they should go to professional institutions for diagnosis in time; Third, early treatment: if cancer is diagnosed, comprehensive treatment based on surgery should be carried out at an early stage;

3. Tertiary prevention: For patients with non-early cancer, through palliative treatment, the survival time of patients can be extended to the maximum extent, and the pain caused by cancer and the negative impact on family and society can be minimized.