The main method of colorectal cancer screening and its detection principle
Release date: 2016-12-09 According to the 2015 China Cancer Status Report, the annual death toll of colorectal cancer is 191,000, and the new incidence is 376,000. The incidence of colorectal cancer is higher in urban areas than in rural areas, higher in high-income areas than in low-income areas, males are higher than females, and older people are characterized by high incidence. This is related to changes in residents' lifestyles, including more meat, less grains, less fruits and vegetables, high protein, high fat, less fiber irrational dietary habits, insufficient physical activity time and intensity, and increased overweight and obesity. The progression of colorectal cancer is a slow natural course. It has been clarified that more than 95% of colorectal cancers are stepped from the large intestine polyps, from small polyps to large polyps to severe dysplasia to carcinoma in situ to invasive carcinoma. It takes 5-10 years. Most colorectal cancers are suitable for early diagnosis and early treatment because of their well-defined precancerous lesions. Colonoscopy can directly observe the changes of the intestinal wall and intestinal lumen, and can determine the location, shape and extent of the tumor, and can take the living tissue for pathological examination. It has high diagnostic value and is the current clinical intestine. The gold standard for cancer diagnosis. Doctor's advice: People over the age of 45 should have a colonoscopy. The shortcoming of colonoscopy as an early screening for bowel cancer is invasive examination, the cost is not low, it requires preoperative preparation, there are certain examination risks and missed examinations, patient compliance is poor, colonoscopy experience is strong, and research shows colonoscopy Screening does not reduce the incidence of right colon cancer. In addition, as an early screening project, it is also a challenge in terms of medical resources and social burden. The fecal occult blood test is currently the most widely used screening technique. Only the subject is required to provide feces, and the fecal sample is collected to detect the hemoglobin content to determine whether cancer has occurred. The advantage is non-invasive, safe, and the subject is well compliant, and the disadvantage is the low specificity and sensitivity of the diagnosis. The traditional fecal occult blood test (gFOBT) can only detect 30-50% of colorectal cancer and 10-30% of precancerous adenomas; the new immunochemical method of fecal occult blood test (iFOBT) can detect 50-60% of the large intestine Cancer and about 30% of precancerous adenomas. Fecal-specific DNA testing is a novel method for early detection of colorectal cancer, which is used to screen for colorectal cancer and precancerous adenomas by detecting genetic changes in fecal specimens. Its detection principle: by detecting the components of exfoliated tumor cells in the feces, to determine whether the subject is likely to have colorectal cancer or precancerous adenoma molecular diagnostic techniques, the most commonly detected tumor cell components are mutations or Humanized human genes. Colorectal tumors generally occur in the colorectal epithelial tissue and grow in the intestinal lumen. During the growth process, tumor cells are continuously shed into the intestinal lumen and excreted with the feces. Therefore, the detection of tumor cell components in the feces can be performed. A non-invasive screening method for colorectal tumor diagnosis is provided. Mutations in tumorigenesis-related genes are tumor-specific, and the methylation level of the gene promoter region is significantly increased in tumor cells compared to normal cells, so changes in these two genes can be used as tumor markers for screening. Or diagnose a large intestine tumor. The technical advantages are mainly as follows: 1. Completely non-invasive, only 4.5 grams of feces, high acceptance of asymptomatic people 2. High accuracy, in the preclinical study can detect the absolute majority of colorectal cancer and most of the precancerous adenoma; can detect 91% of early colorectal cancer, 64% of precancerous adenoma (≥ 1 cm) , specificity is 93% 3. Can simultaneously find tumors on the left and right sides of the colon, reduce detection of blind spots and missed diagnosis 4. Not only can you find colorectal cancer, but you can also find precancerous adenomas, which provides the possibility of preventing colorectal cancer by removing precancerous adenomas. 5. Convenient operation. After obtaining the test kit, the user can complete the sample collection work at home, and then send it by the professional for testing. Through a comprehensive questionnaire survey, fecal occult blood test (immunochemical method), fecal DNA test, these non-invasive methods can screen out high-risk groups susceptible to colorectal cancer, and then enteroscopy, greatly improve the detection of colorectal cancer. rate! Source: Contributed by Cancer Screening and Prevention Center, Shanghai International Medical Center Agaricus Blazei Extract,Matsutake Mushroom Extract,Tricholoma Matsutake,Agaricus Mushroom Extract Shaanxi Zhongyi Kangjian Biotechnology Co.,Ltd , https://www.zhongyibiology.com