Reports from the World Health Organization (WHO) and some Asian countries indicate that the incidence of CRC is rising rapidly in China, Japan, Korea and Singapore. However, the degree of increase varies from country to country. In some East Asian countries, such as Indonesia, Thailand, Vietnam and India, CRC is not the most common malignancy. The incidence of CRC in the Asia-Pacific region is similar to that in the West. In the Asia-Pacific regions with a high incidence of CRC, such as Japan, South Korea, Singapore, and Hong Kong, China, the incidence of this tumor is similar to that in Western countries. In these countries and regions, the “Westernized” lifestyle is more pronounced, especially the diet, with increased consumption of high-fat, high-protein diets and lower intake of fiber. However, in other countries, such as India, the Philippines and Vietnam, the incidence of CRC is at a lower level than in Western countries. Advanced colorectal tumors were defined as adenomas ≥10 mm in diameter, villous adenomas, highly atypical hyperplasia, or invasive carcinomas. In a survey of asymptomatic populations in Hong Kong, 4.4% of individuals had advanced colorectal tumors. Screening colonoscopy in asymptomatic populations in China and Korea showed an incidence of advanced colorectal tumors of 4.1% and 3.0%, respectively, which is comparable to the results of some large-scale screening colonoscopies in Western countries. CRC mortality rate declines in the West, but continues to rise in Asia The American Cancer Society reported in 2007 that the number of deaths from cancer in this country has been declining for the second consecutive year, which may be related to the decline in smoking among men and extensive colon cancer screening. In Europe, the CRC mortality rate is also on the decline. In contrast, the WHO mortality database shows that the CRC mortality rate in Taiwan has increased exponentially over the past 30 years. The National Cancer Center of Korea reported that the mortality rate of gastric and liver cancers in that country has declined, while the mortality rate of CRC has increased. China’s census also confirms a decline in mortality associated with esophageal, gastric, and liver cancers and an increase in CRC mortality in men. Racial susceptibility to CRC exists in Asia Evidence suggests that there are racial differences in susceptibility to CRC. In Singapore, the incidence of CRC is significantly lower in Indians and Malays compared to Chinese, and several studies by the CRC Asia-Pacific Working Group have shown that the risk of advanced colorectal neoplasia is higher in Japan, Korea and China. Colorectal tumor screening methods FOBT, fiberoptic sigmoidoscopy, and colonoscopy are recommended for screening for CRC in the United States and the United Kingdom National guidelines recommend fecal occult blood testing (FOBT), fiberoptic sigmoidoscopy, and colonoscopy for screening for CRC Although rehydration of fecal specimens is not recommended, although it can increase the sensitivity of the test, the false-positive rate is also elevated, which can lead to unnecessary worry and invasive testing. Rehydration of stool samples is not recommended for CRC screening. Immunologic methods are more sensitive than guaiac, especially in Asians, and this may be related to the fact that they are not influenced by diet. The sensitivity of fiberoptic sigmoidoscopy for the detection of advanced tumors has been reported to be 35% to 70%, and it reduces the risk of cancer in the rectum and sigmoid colon by 50% to 60%. Fiberscope sigmoidoscopy should be performed at shorter intervals than colonoscopy because of its lower sensitivity. DCBE is not the method of choice for CRC screening, and in some North American guidelines, a gas-barium double-contrast enema (DCBE) examination once every 5 years is listed as one of the CRC screening methods. However, DCBE is less sensitive than colonoscopy and cannot remove polyps or take biopsies, so the consensus panel did not recommend DCBE as a first-line screening method for CRC. CTC is not currently the preferred method for CRC screening. There is increasing evidence that CT colonography (CTC) is an accurate method for detecting colorectal tumors in the asymptomatic general population, but the high cost, radiation-related risks, and the high requirement for bowel preparation have hampered the widespread use of CTC. Therefore, at this stage, the consensus panel does not recommend CTC as a screening tool for CRC. As the technology becomes more widely available, it is likely to become a recommended CRC screening tool in the near future. FOBT is the method of choice for CRC screening in countries with limited healthcare resources, and its use in screening allows limited colonoscopy resources to be used in individuals who are more likely to have tumors. Although FOBT is not particularly accurate, its simplicity and acceptance by asymptomatic populations have made it the best method of population screening in many Western countries, even those with well-developed healthcare systems. In Asian countries, where resources are limited, FOBT is undoubtedly the most affordable screening method. Even if the colonoscopy is negative, it should be repeated within 10 years. Colonoscopy is not perfect and may miss some adenomas or even carcinomas. The rate of new or missed CRCs within 3 years of colonoscopy has been reported to be 5% in the proximal colon and 2% in the distal colon.