What is the possible pathogenesis of colon cancer

Like other tumors, the exact pathogenesis of colon cancer is still not very clear. The incidence of colorectal cancer in Chinese and Japanese is significantly lower than that in Americans, but the first generation of immigrants to the United States can see an increase in the incidence of colorectal cancer, and the second generation is basically close to the incidence of Americans. From an epidemiological point of view, the incidence of colon cancer is related to the environment, lifestyle, and especially eating habits. Studies have shown that a diet rich in saturated fatty acids can increase the concentration of bile acids and neutral sterols in the colon and change the composition of the coliform flora. Bile acids can generate carcinogens such as 3-methylcholanthrene through bacterial action, and sterol rings can also be aromatized by bacteria to form carcinogens. Dietary fiber includes cellulose, pectin, hemicellulose, lignin, etc., which can absorb water, increase stool volume, dilute the concentration of residues in the intestine, shorten the time it takes for stool to pass through the large intestine, and reduce the contact time between carcinogens and intestinal mucosa. If there is insufficient dietary fiber in the diet, it will lead to