World Health Organization has pointed out that the secondary prevention of cancer is early detection and timely treatment. Census is the early detection of oral cancer is an important measure of China's population had been large-scale census. For example, in the 20th century, Shanghai Textile late 50s to carry out a cervical cancer screening. About the early 70s from the 20th century carried out a census of digestive system cancer. Linxian in Henan and a number of areas, has carried out surveys of esophageal cancer in order to pull the net as the main method for cytological examination. Qidong, Jiangsu, Guangxi Fusui, some areas in Guangdong and Shanghai, had carried out the census population of liver cancer, detected as the main method to AFP. The above survey, have found many many precancerous lesions and early cancer. Cancer screening involves the following questions.
Digestive system introduced anti-cancer screening (a) of the census method
Survey methods, requiring sensitive, convenient, low cost, missed little. Blood test for liver cancer AFP by the census. General census methods used hemagglutination AFP. Hemagglutination fast, a lot of testing, but the accuracy is not enough. Positive by the hemagglutination method survey, for further quantitative alpha-fetoprotein, or convection, agar diffusion tests such as alpha-fetoprotein elevated indeed, go further to make B-, CT or other tests. Gastric and intestinal cancer, can often check the stool for occult blood. Fecal occult blood positive, further examination of stomach, or large intestine. Gallbladder, pancreas lack of screening methods. B-test is generally on a regular basis.
Digestive system introduced anti-cancer screening (b) the costs and benefits between the census
This is a recent national census to be taken into account. Liver cancer in the early 20th century, 70 had been large-scale population census. Number of more than one million census, but the investigation was relatively small in the early liver cancer, mostly in the late Yuan and thus the survival rate and significantly improved. 60 to the 20th century, Shanghai's with complete data, for example, the 20th century, the survival rate for liver cancer 70,80, and 60 years no significant difference. Therefore, the basic work of a large-scale survey of liver cancer to stop. Esophageal cancer screening method for esophageal cytology dragnet, the method is not too simple, the subject has some discomfort. Only in the high incidence, there are the possibility of a comprehensive survey, but the lack of randomized controlled data to illustrate the census does reduce morbidity and mortality, and thus not suitable for comprehensive promotion of the census. For stomach cancer, Japan, began in the 20th century 60 large-scale census. X-ray imaging method, after a gastroscopy. According to reports, a total census of millions of people, and the detection of gastric cancer was 0.12%. Or only limited to the mucous membrane of early cancer are almost close to half. Stomach cancer mortality was significantly lower than the census period, the survival rate was significantly higher than that investigation group. It is generally believed, confined to economic strength, equipment conditions, China is not yet appropriate for general promotion. Colorectal cancer screening, the occult blood test-based, such as a positive, further colonoscopy. But consider the economic and clinical value, and it is not widely used.
Digestive system introduced anti-cancer screening (c) the scope of the census
It is generally preferred screening high-risk groups, in preference to large-scale population census. But the high risk inspection, there are still some problems. Example, family history of liver cancer, hepatitis B patients with liver cirrhosis can be considered high risk. Primality of hepatitis B disease in patients with cirrhosis of the liver alpha fetoprotein screening, is still not cost-effective principles. Because hepatitis B and liver function in patients with liver cirrhosis and liver are not suitable for the nature of a large number of liver resection, liver cancer or even if discovered earlier liver cancer, treatment, there are still many difficulties; Even if the surgery, the prognosis also poor. After a family history of testing, such as HCC, the general prognosis than those without family history for the worse. Therefore, the liver cancer risk population census, is still not necessarily reduce mortality and improve the survival rate to resolve the issue. Esophageal cancer in high-risk groups, such as esophageal epithelial hyperplasia; high risk for stomach cancer tip of intestinal metaplasia, the diagnosis itself to be pulled by the network or esophageal endoscopy to make. Survey of such high-risk groups, nor can the general conduct of clinical units, offenders are usually not accepted by patients. Like colon polyps can be considered in patients at high risk of colon cancer, but such checks offenders are usually not accepted by patients. Therefore, screening high-risk populations, or because of method has certain limitations, or because of death, little effect on survival has yet to be widely carried out.
Digestive system introduced anti-cancer screening (d) assessment and recommendations census
Overall, the survey should aim to reduce mortality and improve long-term survival. To this aim must be to develop prospective randomized program, planned for, and the need for practical methods. Methods should be simple, accurate and no big pain. On this basis, the establishment survey agencies to develop implementation plans to determine the census estimates, a comprehensive survey, and digestive system cancer mortality reduction by screening and by 5 years, 10-year survival rate, is hard to do in the near future.