| ?Background?Ulcerative colitis(UC)is a common type of inflammatory bowel disease(IBD).It is a kind of chronic relapsed non-specific intestinal disease caused by the interaction of multiple factors including heredity,immunity,environment and intestinal microorganism.The exact cause of UC was unknown.UC associated colorectal cancer(CRC)was a serious complication of UC.Patients with longstanding UC have a high risk of developing colorectal cancer.Dysplasia is a precancerous lesion of UC-CRC.In order to achieve early detection and treatments of dysplasia,regular endoscopic examination with biopsies is an important way to prevent the occurrence of CRC.Due to the UC related dysplastic lesions are mostly flat lesions,so several international guidelines recommend the use of white light endoscopy(WLE)with sequential 4-quadrantic random biopsies every 10-cm interval colon in the surveillance of UC related dysplasia and CRC.However,this method had been longtime debated and was time-consuming and costly.A notable portion of physicians did not follow these recommendations in the daily clinical practice and obtained biopsies from targeted lesions only.Chromoendoscopy(CE)is a method to conduct dye spraying on intestinal mucosa under conventional white light endoscopy,so as to enhance visualization of subtle abnormalities in colonic mucosa and make the biopsy more accurate.Data from single center experience or small sample-size studies have shown that chromoendoscopy(CE)might be superior to white light endoscopy(WLE)in dysplasia surveillance without longitudinal surveillance.The identification of risk factors for UC-CRC can effectively distinguish low-risk and high-risk patients and is beneficial to conduct effective personalized monitoring.Finding out the risk factors of UC-CRC in Chinese UC patients is of great significance to guide the monitoring of UC-CRC in China ?Aim?1.We performed a prospective randomized trial with a long-term follow-up to compare detection rate of dysplasia among conventional targeted biopsies using WLE(conventional method,CM),WLE with random biopsies(WLR)and CE with targeted biopsies(CET)during dysplasia surveillance in UC patients.2.To determine the risk factors of dysplasia or CRC in Chinese longstanding UC patients.?Methods?1.Patients with longstanding UC were enrolled from eleven centers and randomized into three arms of the study from Mar 2012 to Dec 2013.The patients were followed up by annual endoscopy with biopsy through December 2017.All biopsies were histopathologically examined,neoplastic lesions were recorded according to their location and morphology.Compare the detection rate of colonoscopies diagnosed with dysplasia,patients diagnosed with dysplasia and dysplastic lesions among the three groups.2.All patients were divided into two groups according to the presence or absence of dysplasia or CRC,and Cox proportional risk model was used for analysis to identify the risk factors of dysplasia or CRC in UC patients in China.?Results?1.With a median follow-up time of 55 months,a total of 122 patients(69 men;mean age 45.8±12.04 years)with 447 colonoscopies were final analyzed: CM(n=43),WLR(n=40)and CET(n=39).A total of 34 dysplastic lesion were found in 29 colonoscopies of 21 patients.WLR and CET could detect more colonoscopies diagnosed with dysplasia than CM(8.1% vs 1.9%,P=0.014;9.7% vs 1.9%,P=0.004).There was no significance difference between WLR and CET group(P=0.642).WLR and CET could detect more patients diagnosed with dysplasia than CM(25.0% vs 4.7%,P=0.008;23.1% vs 4.7%,P=0.014).There was no significance difference between WLR and CET group(P=0.842).WLR and CET could detect more dysplastic lesions than CM(9.5% vs 2.6%,P=0.012;11.0% vs 2.6%,P=0.004).There was no significance difference between WLR and CET group(P=0.657).WLR(mean 16.4,SD 5.1)had taken more biopsied samples than CM(mean 4.3,SD 1.4)and CET(mean 4.3,SD 1.4)(P=0.000,P=0.000).After 3 years of follow up,CET detected more dysplasia than the CM(13.3% vs 1.6%,P=0.015)and had a trend of increasing detecting rate compared with WLR(13.3% vs 4.9%,P=0.107).There were more non-polypoid dysplastic lesions detected in CET group than CM group(9 vs 1,P=0.007)and WLR group(9 vs 0,P=0.001).2.Extensive colitis(HR 3.40;95% CI 1.32-8.76)and disease duration(HR 2.74;95% CI 1.07-7.06)were associated with colonic dysplasia in longstanding UC patients in China.?Conclusions?1.For a better outcome of cancer/dysplasia surveillance for patients with longstanding ulcerative colitis,chromoendoscopy with targeted biopsy appeared to be more effective than conventional colonoscopy and less tedious than random biopsy technique.Chromoendoscopy with targeted biopsy became particularly useful when a long-term(>3years)follow-up was conducted for dysplasia surveillance in UC patients.2.Extensive colitis and disease duration of more than 10 years are two independent risk factors for dysplasia in UC patients in China.Monitoring should be strengthened for patients with longstanding and extensive colitis. |
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