Dataset Information

Study on narrow band imaging versus conventional colonoscopy for polyps detection in patients with positive fecal occult blood test undergoing colonoscopy screening

ABSTRACT: Background and study aims The detection and removal of adenomatous polyps (small non-cancerous growths that develop in the large bowel) may prevent colorectal cancer and save lives. Colonoscopy is the standard procedure for the detection and removal of polyps. However, colonoscopy still misses between 5% and 24% of polyps, which can result in the development of colorectal cancer. It is also unable to distinguish different types of polyp, leading to the removal of all polyps found, thus increasing the costs and risks. In order to overcome these limitations, there have been many attempts to improve the diagnostic accuracy of colonoscopy. The aim of this study is to find out whether the use of a new endoscopy technology called narrow band imaging (NBI) increases the detection rate of advanced adenomas compared with High Definition White Light colonoscopy (HD-WL). Who can participate? Patients aged 55-64 undergoing colonoscopy What does the study involve? Participants are randomly allocated to undergo colonoscopy with either HD-WL or NBI. The colonoscope is inserted into the rectum and advanced to the cecum (the beginning of the large intestine). The endoscopist carefully explores the whole colon, and the procedure is timed by the endoscopist using a stopwatch. Polyps detected are documented for their size, location and shape, and removed and sent in separate jars for diagnosis by a histopathologist. The number of adenomas and advanced adenomas are counted in both groups.

DISEASE(S): Patients With Positive Fobt Harbour A Risk Of Colorectal Cancer Of About 5% And Of Advanced Adenomas Of About 40%

PROVIDER: 2421677 | ecrin-mdr-crc |

REPOSITORIES: ECRIN MDR

ACCESS DATA

Similar Datasets

Project description:Colorectal cancer often arises from adenomatous polyps. Polyps can grow and progress to cancer, but may also remain static in size, regress, or resolve. Prediciting which progress to cancer and which remain benign is difficult. We developed a long-lived murine model of colorectal cancer with tumors that can be followed by colonoscopy. Our aim was to assess whether these tumors have similar growth patterns and histologic fates to human colorectal polyps to identify features to aid in risk stratification of colonic tumors. Long-lived Apcin/+ mice were treated with 4% dextran sodium sulfate to promote colonic tumorigenesis. Tumor growth patterns were characterized by serial colonoscopy, and pathology was determined. Serial biopsies of tumors were obtained for immunohistochemistry and gene expression profiling by microarray analysis with Affymetrix Whole Genome array. Tumors (n=424) grew, remained static, regressed, or resolved over time with different relative frequencies. Newly developed tumors demonstrated dynamic growth patterns with higher rates of growth and resolution, while more established tumors tended to remain static in size. Colonic tumors were hyperplastic lesions (3%), adenomas (73%), intramucosal carcinomas (20%), or adenocarcinomas (3%). Differentially expressed genes between adenomas and intramucosal carcinomas were identified. We did not identify differentially expressed genes between early and late biopsies from the same tumor. This novel murine model of intestinal tumorigenesis develops colonic tumors that can be monitored by serial colonoscopy, mirror growth patterns seen in human colorectal polyps, and progress to colorectal cancer. Further characterization of cellular and molecular features are needed to determine which features can be used to risk-stratify polyps for progress to colorectal cancer and potentially guide prevention strategies. F1 (SWR x C57BL/6) Apcin/+ mice who had been given two treatments of 4% dextran sodium sulfate in drinking water at weaning underwent colonoscopy around 80 days of age. Those with distal colonic tumors amenable to biopsy had two biopsies taken at that time. Tumors were monitored by colonoscopy every 14 days. Every 28 days, two additional biopsies were taken of each tumor. This protocol was repeated until mice were moribund. Six tumors were removed after sacrifice. The earliest and latest biopsies of each tumor were selected for RNA extraction and Affymetrix hybridization.

Project description:Adenomas, serrated adenomas and hyperplastic polyps are polypoid lesion in the colorectum. At the present moment, all polyps should be resected endoscopically, although only adenomas and serrated adenomas, but not hyperplastic polyps have the potential to develop colorectal cancer. This approach enables the conduction of microscopic investigations of the lesions. By today, only the pathological diagnosis can distinguish exactly between these three polyp entities. Some studies have investigated the value of the optical characterization approach which is based on visual assessment of the polyp’ surface structures. Based upon optical polyp features users are encouraged to predict histopathological polyp diagnoses solely on behalf of optical or endoscopical criteria. This method is conducted in real time during colonoscopy. If it could be shown, that endoscopist using the optical characterization approach are able to predict histopathological diagnoses of colonic polyps sufficiently this would possibly lead to simplification of diagnostic procedures. For instance, it would be conceivable to resect small polyps and discard them without further assessment by a pathologist. One problem in this context is a correct differentiation between hyperplastic polyps and serrated adenomas. These two polyp entities are known to show similar optical features. However, while serrated adenomas are premalignant lesions hyperplastic polyps have benign histology and never develop into cancer. It is therefore important to sufficiently distinguish hyperplastic polyps from serrated lesions. In this study we want to investigate whether the use of narrow-band imaging (NBI) would be capable to rise accuracy of optical polyp predictions compared to standard HD white light endoscopy. NBI is a light filter tool which can be activated by pressing a button at the endoscope. The use of NBI leads to an endoscopic picture which appears blue and enables endoscopists to better assess surface structures and vascular patterns. In a prospective randomised multicenter setting we plan to conduct colonoscopy in 370 patients. Half of the patients will be examined without the use of NBI (control arm). In these cases colonoscopists will assess optical diagnosis of polyps without turning on the NBI tool. If polyps are detected in patients belonging to the intervention arm NBI will be used and optical diagnosis will be determined using the WASP (Workgroup serrAted polypS and Polyposis) classification. All polyps will be resected and send to pathology for further microscopic assessment. After completing the trial we aim to compare accuracy of the optical diagnosis in both groups. Our hypothesis is, that by using NBI accordance between optical and histopathological diagnosis can be increased from 80% to 90%.

Dataset Information

Study on narrow band imaging versus conventional colonoscopy for polyps detection in patients with positive fecal occult blood test undergoing colonoscopy screening

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets