The incidence of colorectal cancer in China is increasing day by day, and how to properly prevent and treat colorectal cancer has become an issue of concern for many people, especially elderly people. In the United States, 1.5 million people unfortunately fall ill and 60,000 people lose their lives due to it every year. Colorectal cancer has become the third cancer killer in terms of new cases and mortality. In China, the incidence of colorectal cancer is on the rise, and the growth rate of incidence in major cities such as Beijing and Shanghai has far exceeded that of western countries. More seriously, with the accelerated aging of the population and changes in living habits and dietary structure, the incidence of colorectal cancer continues to rise nationwide. It is urgent to prevent and treat colorectal cancer. Modern medicine believes that colorectal cancer is a preventable and curable tumor. Firstly, colorectal cancer mostly starts with adenoma and has a long development process. If precancerous lesions can be detected and removed early, the occurrence of cancer can be effectively prevented. Secondly, there are more studies on the causative factors of colorectal cancer, which provides a theoretical basis for cancer prevention. Thirdly, early treatment of colorectal cancer is very effective and can completely achieve cure. Therefore, we should have confidence in the prevention and treatment of colorectal cancer. The United States is currently one of the best countries in the prevention and treatment of colorectal cancer. Since the mid-1990s, the incidence and mortality rate of colorectal cancer in the United States have gradually decreased, and the 5-year survival rate of colorectal cancer is now 64%, and the early stage can reach 90%. Their experience is mainly a balanced diet, promotion of screening, timely removal of precancerous lesions and promotion of physical exercise. I will discuss each of these aspects below. ”Prelude” – Balanced diet “Colorectal cancer is a cancer that comes out of eating” is a very reasonable saying. As the saying goes, disease enters from the mouth. If you eat a lot of high-oil and high-fat food and do not exercise, your intestines will follow and become lazy, and peristalsis will slow down, and toxic substances will accumulate in your intestines for a long time, thus cancer will occur. Therefore, we advocate a healthy and balanced diet. 1.High fiber After the nutrients in food are absorbed, the remaining substances form feces, and the colon is the main place for the formation and storage of feces, so it can be said that the colon is the most filthy place among the organs of the human body, which is one of the reasons for the occurrence of colon cancer. Fiber plays an important role in maintaining a healthy digestive system, and modern medical research shows that a high fiber diet greatly reduces the incidence of colorectal cancer. The main role of fiber in the intestinal tract is like a scavenger, and the mechanism of high fiber diet to prevent colorectal cancer is as follows: First, “intestinal vacuum cleaner”: fiber can adsorb carcinogenic substances in feces, such as nitrosamines and polycyclic aromatic hydrocarbons, so that these carcinogenic substances are excreted from the body with feces. Second, “intestinal power gas pedal”: fiber is mostly indigestible, so it can increase the volume of stool, promote the peristalsis of gastrointestinal tract and speed up the excretion of stool, thus promoting the excretion of carcinogenic substances as soon as possible. Thirdly, “intestinal mucosa protector”: food fiber can eliminate the adverse stimulation of bile on intestinal wall cells to the greatest extent and protect intestinal cells from damage, thus reducing the probability of intestinal cancer. Fourth, the risk of colorectal cancer is related to the total energy intake of the body, and reducing energy intake can reduce the incidence of colorectal cancer. A high-fiber diet can replace the amount of some nutrients in food, thus reducing the total food intake, which means less energy intake. In addition, a high-fiber diet can make the body feel full and suppress the desire to eat. In addition, fiber is combined with some fatty acids, and this combination makes the fatty acids cannot be absorbed when they pass through the digestive tract, thus reducing the absorption rate of fat and preventing the body from becoming too obese, which is also a risk factor for the development of colorectal cancer. 2.Low fat As we all know, meat is the main source of fat in the diet. High-fat diet can increase the secretion of liver bile and increase the excretion of bile acids, which are transformed into carcinogenic substances – methylcholanthrene by enzymes in the body, and methylcholanthrene can directly induce carcinogenesis of intestinal mucosa cells. In addition, bile acids are transformed into deoxycholic acid and lithocholic acid by intestinal bacteria, both of which are cancer-promoting substances. This is because high concentration of bile acids can cause non-specific damage to intestinal tissue cells, which can directly damage DNA, induce epithelial proliferation, and inflammatory damage and repair of intestinal wall tissues in the important process of tumorigenesis. How to reduce the fat in the diet? ① Eat more low-fat foods (skim milk, low-fat yogurt, etc.). ②consume more olive oil and reduce the intake of butter and vegetable oil (such as salad oil and cream). ③It is advisable to eat lean meat. Such as chicken with the skin removed, fish and shellfish, etc. 3.Reject junk food Among the world’s top ten junk foods announced by the World Health Organization, there are at least six types of foods that can lead to colorectal cancer: fried foods, pickled foods, processed meat foods (containing nitrite), convenience foods, plum preserves, and barbecue foods. For example, when baking meat, polycyclic aromatic hydrocarbons (PAHs) will be attached to the meat, of which benzo(a)pyrene is a very strong carcinogen. According to laboratory tests, the amount of polycyclic aromatic hydrocarbons formed in a piece of charcoal grilled steak is comparable to the amount in 600 cigarettes smoked. Therefore, the above-mentioned foods should be avoided. ”In the 1990s, foreign clinicians noticed an interesting phenomenon that the incidence of colorectal cancer was much higher in white-collar workers (office workers, etc.) than in blue-collar workers (high-intensity physical workers). Subsequent evidence-based medical studies have shown that body mass index (BMI, weight in kilograms divided by height in meters squared, is a measure of body fatness and thinness.) The relative risk of colon cancer was increased by nearly 1/2 in people with more than 29 compared to those with BMI less than 21. This suggests that overweight and obesity are risk factors for colon cancer. In recent years, a similar phenomenon can be observed in China, where some elite people in their 40s developed colon cancer. They all have one thing in common: they are busy with work and lack of leisure sports and exercise. According to British scientists, exercise can reduce the risk of colorectal cancer by half, and leisure activities such as physical exercise, manual labor, walking or gardening can keep people away from bowel cancer. Studies have also shown that people who exercise regularly are less likely to develop bowel cancer, even if they have risk factors such as excessive obesity and smoking. Therefore, the World Health Organization clearly affirms that physical activity is beneficial in reducing the incidence of colorectal cancer. ”Symphony” – Promote Screening With the improvement of living standard, regular medical checkups are increasingly valued by people. Many patients have early detection of colorectal cancer through regular physical examination and screening, and have achieved better treatment results. Basic screening items: There are three basic screening tests for colorectal cancer: stool occult blood test; anal finger test; tumor markers such as CEA and CA19-9. However, the reality is that many people neglect the first two tests. 80% of colorectal cancer patients have blood in stool, and due to the small amount of bleeding, more than half of the blood in stool is not visible to the naked eye, which needs to be screened by stool occult blood test. Most people feel uncomfortable or embarrassed, and doctors sometimes find it troublesome, and the test must be performed in a private place, so many people choose to give up. In fact, unlike Europeans and Americans, more than 70% of rectal cancers in Chinese are low rectal cancers, and the cancer can be palpated during rectal finger examination. Therefore, these three examinations are mandatory for screening colorectal cancer. Patients with abnormalities in these three examinations should undergo colonoscopy for further clarification. Be alert to early symptoms: defecation several times a day or not once in several days; stool suddenly turns into thin strips; stool turns from yellow to black or mixed with red blood color …… because it is not painful or itchy, most people may ignore it. In fact, these may be the “alarm” signals sent by colon cancer. In many cases, the detection of disease is not due to physical examination, but according to the early manifestations of most diseases. Early symptoms of colorectal cancer are insidious and easily confused with many other diseases, which may be missed or misdiagnosed by doctors and patients due to negligence. For example, it is common to see patients with rectal cancer being misdiagnosed as hemorrhoids in the early stage. In the early stage of colorectal cancer, there will be bleeding and blood in stool, mucus and pus, change in bowel habit, alternating diarrhea or constipation, abdominal pain and bloating, anemia and emaciation, etc. To sum up, blood in stool, change of stool habit and trait are all early warning signs of colon cancer, so if the above symptoms appear, you should go to hospital for relevant examination in time. ”Resonance song” – remove precancerous lesions Precancerous lesions of colon are relatively clear, mainly colorectal adenoma, familial adenomatous polyposis and ulcerative colitis, etc. Colorectal adenoma is currently recognized as a precancerous lesion. When the diameter of adenoma is greater than 2cm, the cancer rate is up to 30% or more. Especially in familial adenomatous polyposis, the cancer rate is as high as 90% before the age of 45. Colonic adenoma is divided into tubular adenoma and villous adenoma, the latter is more prone to malignancy, with a cancer rate of up to 50%. The inflammation of the intestinal tract in patients with ulcerative colitis can lead to repeated destruction and repair of the intestinal mucosa, and the incidence of colorectal cancer increases with the prolongation of the disease and the expansion of the lesion. Therefore, for patients with ulcerative colitis, those with personal or family history of colorectal cancer or adenoma, early removal of adenoma and treatment of colitis through screening and follow-up can reduce the incidence and mortality of colorectal cancer.