| Background:Colorectal cancer is a serious threat to human health, deoxycholic acid(DCA) plays a certain role in carcinogenesis and progression of the colorectal cancer. But the prognosis can be significantly improved through prevention, early diagnosis and treatment which is based on screening, colonoscopy surveillance and causative factors. Therefore it is worthy to be investigated in-depth for the strategy of colorectal cancer screening, colonoscopy surveillance and the mechanism of colorectal cancer induced by deoxycholic acid, especially in the current situation of china.Objectives:1. Study the risk factors of colorectal tumor in the community population and hospital outpatient patients, explore colorectal cancer screening model and the optimal colonoscopy surveillance interval.2. Explore the carcinogenesis and progression of the colorectal cancer induced by deoxycholic acid.Methods:1.Between 2011 to 2013, the samples(3338 persons) come from the resident population of the Han nationality from 18 to 90 years old, were randomly selected from two communities, Lianran and Jinfang community, Under the District of Anning, Kunming, Yunnan province. And the other samples(2000persons) were selected from the outpatients of The First Affiliated Hospital of Kunming Medical University.they were invited to complete a self administered questionnaire which consist of the information of themselves, then completed a colonoscopy to confirm whether the colorectal tumor existence. Explore the risk factors of colorectal tumor to design a colorectal cancer screening strategy, that is find high-risk individuals of colorectal tumor through completed questionnaire firstly, and then the colonoscopy for them.2. Selected The patients with intact data who undergone two times more colonoscopy in the endoscopic center of the gastroenterology, the First Affiliated Hospital of Kunming Medical University from 2000 to 2013. And all of the polyps found at first colonoscopy have been removed by colonoscopy completely. Analysis the risk factors of adenoma recurrence and the optimal colonoscopy follow-up surveillance interval among the non-adenomatous polyps, the adenomas, the advanced adenomas and the normal participants.3. CCD 841 CoN (Human normal colonic epithelial cells) and Min mice as a model, they were treated with DCA in different concentrations. Then explore the intestinal mucosal cell proliferation, apoptosis, Wnt signaling pathway protein (β-catenin protein) change and observate Min mice intestinal tumorigenesis and the adenoma malignant transformation.Results and Conclusions:1.The high risk factors obtained from the questionnaire can be used as a usefull tool for community and outpatient colorectal cancer screening. 2. gender, age, history of cancer or a history of intestinal polyps, chronic diarrhea, chronic constipation, mucous and bloody stool, hypertension, smoking, high intake smoked or fried food were shown to be associated with the risk for colorectal cancer and precancerous lesions.3. The increased risk for colorectal cancer following chronic cholecystitis and cholelithiasis seems to be due to a process occurring after the adenoma has developed or beside the pathways of colorectal adenoma-carcinoma. 4. Gender, age, polyps distribution, adenoma size and position are associated with the Risk factors of adenoma recurrence or detection of adenoma by colonoscopy follow-up surveillance.5. The optimal colonoscopy surveillance interval is 4.76 (95% CI,4.32-5.22) years for normal cases in the primary colonoscopy,3.32 (95% CI, 2.79-3.87) years for the non-adenomatous polyps,2.85 (95% CI,2.53-3.17) years for the adenomas and 2.06 (95% CI, 1.71-2.45) years for the advanced adenomas.6. DCA promots colon epithelial cell proliferation and colorectal cancer formation, this effect is through β-catenin translocation, then activation of Wnt/β-catenin signal pathway. |
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