According to data from the Ministry of Health in 2009, cancer deaths accounted for the first cause of death in China, with more than 22% of the country’s population dying from malignant tumors. Without further measures to curb cancer, it is expected that by 2020, there will be 20 million new cancer cases and more than 10 million cancer deaths each year. This past February 4 is the “Spring” day, which is also the World Cancer Day. It reminds people that early prevention of cancer is important. Especially, healthy habits should be developed during childhood. Epidemiological studies have found that about 40% of cancers can be prevented. Primary prevention Health education and self-care Many people think that cancer is a “fate” and only “unfortunate” people suffer from it. In fact, there are internal factors such as heredity and genes, but more than 90% of cancer is caused by external environment, and cancer is not contagious, nor does anything cause cancer. Cancer prevention can be divided into three levels. Primary prevention is carried out through health education, self-care and health care when tumors have not yet formed. For example, lung cancer is the most common primary malignant tumor of the lung. Most lung cancers originate from the bronchial mucosa epithelium, so it is also called bronchial lung cancer. Lung cancer is currently the leading cancer mortality rate in the world. A lot of information shows that smoking and lung cancer are closely related. Paper cigarettes contain many carcinogenic substances such as benzo(a)pyrene. Experimental animals inhaling paper cigarette smoke or applying tar can induce respiratory tract and skin cancer. The incidence of lung cancer is 10 times higher in people with smoking habits than in non-smokers; the incidence is even higher in heavy smokers, 20 times higher than in non-smokers. Therefore, lung cancer avoid smoking and alcohol; avoid spicy and stimulating foods such as onion, garlic, leek, ginger, pepper, chili, cinnamon, etc.; avoid hot foods such as frying and barbecue; avoid greasy and sticky foods that produce phlegm. In late stage of lung cancer, the diet should be diversified, light and nutritious, mainly meat porridge, fish porridge, egg porridge, coix rice porridge, lily porridge, wolfberry porridge and other kinds of porridge and soup, together with fruits and fresh vegetables. Secondary prevention Early detection, early diagnosis and early treatment External cancer-causing factors include chemical, physical and biological cancer-causing factors; internal cancer-causing factors include mental factors, nutrition and vitamins, immune status, genetics, endocrine, etc. Secondly, environmental problems, bad habits in diet and smoking can increase the incidence of cancer. Secondary prevention means early detection, early diagnosis and early treatment in the early stage of cancer formation. Stomach cancer, whose incidence rate used to be the first among all kinds of cancers in China. In early stage of gastric cancer, most of them have no symptoms or only slight symptoms. When the clinical symptoms are obvious, the disease is already in advanced stage. Therefore, we should be very alert to the early symptoms of stomach cancer. The main risk factors of gastric cancer are: long-term consumption of high salt, smoked products and salt-pickled food has a role in the occurrence and development of gastric cancer. Bad eating habits, such as eating fast, hot food, not eating three meals a day on time, etc. Those who suffer from atrophic gastritis, gastric ulcer, gastric polyp, intestinal chemosis, pernicious anemia and residual stomach after having most of the gastric resection have the risk of cancer. Those who have family history of stomach cancer, those who are over 40 years old, those who have not been cured of stomach disease for a long time, and those who have A blood type and combined with the above factors are more likely to develop stomach cancer. In terms of diet, people should avoid the intake of high salt, pickled food, rough food and food additives, quit smoking and alcohol, eat more fresh vegetables and fruits, drink more milk, improve eating habits and ways, eat on time, eat quantitatively, avoid overeating, food should not be too hot, and eating should not be too fast. Tertiary prevention Focusing on rehabilitation to improve survival quality Tertiary prevention of cancer is to focus on rehabilitation, which aims to improve the cure rate, survival rate and survival quality of tumor patients by standardizing the diagnosis and treatment plan, providing rehabilitation guidance, and guiding cancer patients on physiology, psychology, nutrition and exercise. Breast cancer is the malignant tumor with the highest incidence in women, with a higher incidence in women between 40 and 60 years old, before and after menopause. The main symptoms are: breast lumps and pain, nipple overflow and changes, skin changes, and enlarged axillary lymph nodes. In addition, infertility, few births, late age of first full-term birth, early age of menarche, history of benign breast disease, family history of genetic predisposition, oral contraceptive use, and radiation exposure have been identified to be associated with breast cancer. Studies have shown that iodine and thyroid hormones (both natural and synthetic) generally reduce the risk of breast cancer. Cancer experts believe that iodine is a crucial element in the fight against cancer, and in Japan, where the prevalence of breast cancer is low, the reason is that Japanese people often eat a diet rich in iodine. To prevent breast cancer, you must avoid smoking, alcohol, coffee and cocoa; spicy and stimulating foods such as pepper, ginger and cinnamon; fatty, fried, moldy and pickled foods; and hairy things such as rooster. The most important thing is to have regular breast examination. 20 to 40 years old women should have a monthly breast self-examination within one week after menstruation and a clinical examination by a professional doctor every two years. 40 to 49 years old women should have a professional breast examination once a year in addition to the monthly self-examination. 50 years old and above women should have a monthly self-examination and a clinical breast examination and mammography once a year.