Would you be surprised if you were told that about 60% of all cancers are avoidable? 57.4% of the overall cancer deaths in China are avoidable. In terms of the causes of incidence, among them, chronic infection is the leading cause of cancer incidence and death, accounting for 29.4%; the second leading cause is active and passive smoking, accounting for 22.61%; followed by various factors such as insufficient consumption of vegetables and fruits, alcohol consumption, occupational exposure and environmental pollution. In fact, different causative factors that lead to the development of cancer eventually produce different types of cancer. It has been shown that there are some cancers that can be caused by long-term chronic infections, such as hepatitis B virus (HBV) may lead to liver cancer; Helicobacter pylori can cause stomach cancer; human papilloma virus (HPV) infection can lead to cervical cancer, etc. Generally speaking, these cancers related to long-term chronic infections mostly occur in less economically developed areas, where the natural environment is often harsh, nutritional conditions are poor, hygiene level is low, and living habits are also bad. Therefore, they are mostly prone to such cancers. Because of the above characteristics, these cancers are often regarded as “poor cancers”. For these viral cancers, vaccines are, in principle, the preferred preventive measure, and in the early 21st century, attempts to prevent and treat these cancers with vaccines have made progress in all viral cancers. Data from Taiwan show that since 1984, when hepatitis B vaccine was administered to 95% of infants and children, the number of hepatitis B carriers decreased from 10-20% to 0.2% after 20 years, and the incidence of liver cancer decreased by 70%-80% accordingly. For some other viruses, such as Helicobacter pylori, a combination of antibiotics can be used to destroy them and relieve gastritis and gastric ulcers, which are very resistant to further development into gastric cancer. Extensive vaccination against hepatitis B and human papillomavirus can significantly reduce hepatitis B virus and cervical cancer virus vaccine, which can significantly reduce the occurrence of liver cancer and cervical cancer. From a preventive point of view, people should enhance their physical fitness, exercise more and be actively vaccinated to make the virus inaccessible. Other cancers are often associated with a high standard of living and eutrophication, and are therefore classified as so-called “rich cancers”, such as lung cancer, breast cancer, colorectal cancer, and prostate cancer. Although about 52% of cancer deaths in our population are attributed to chronic infections and smoking, the effects of diet, alcohol consumption, occupational carcinogens and environmental pollution cannot be ignored. About 2-4% of these tumors are attributed to genetic susceptibility factors, while the vast majority of tumors are caused by environmental factors (or lifestyle). In addition, psychological factors are also a cause of cancer. The occurrence of any disease can find its psychological root. For example, people’s bad emotions such as worry, bitterness and loneliness can make the body’s immune surveillance function decrease, the role of natural killer cells in the body decreases, and the ability to resist tumor cells is greatly reduced, making people more likely to develop cancer. From the perspective of cancer prevention, about 25% of cancers are attributed to alcohol consumption, unbalanced diet, nutritional deficiency and lack of physical activity. Therefore, it is best not to drink alcohol on a regular basis and not to drink very hot and strong tea often. It is important to consume sufficient amount of fruits and vegetables daily. And it is necessary to change the bad lifestyle and increase physical activity, etc. Don’t stay up late often, eat a reasonable diet, replenish the vitamins your body needs, and exercise in moderation are all things we should pay attention to in our daily lives. Psychologically speaking, positive emotion can strengthen the body’s immunity. When we look at the problem with an optimistic attitude, our body will also cooperate with us, so that tumors will not find us easily.