Neoplasms

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Adenoma

Colonic Polyps

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Adenomatous Polyps

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Cola

A transparent cap will be affixed to tip of the high-definition wide angle colonoscope.

4mm transparent cap (Olympus) mounted to the tip of a colonoscope.

Colonoscopy Cap

Heiko Pohl

Effectiveness of screening colonoscopy in cancer prevention relies on the detection and removal of adenomatous polyps. However, a substantial rate of adenomas is missed during a colonoscopy. It has been estimated that two thirds of missed adenomas are located on the proximal aspect of colonic folds. Attaching a transparent cap to the tip of a colonoscope may allow examination of the proximal aspect of colonic folds, and some early studies have suggested an increased polyp and adenoma detection using this technology. However, the studies have in part substantial methodological limitations (e.g. missing polyp histology, single endoscopist study, polyps not removed at the time of detection). Therefore, at this point it is unclear whether cap assisted colonoscopy may improve adenoma detection. The objective of this study is to evaluate whether cap assisted colonoscopy improves adenoma detection.

The investigators propose a two-center multiple endoscopists randomized controlled trial. Patients will be randomized to cap assisted colonoscopy or standard high definition white light colonoscopy. The cap is a 4mm commercially available transparent cap that is attached to the tip of the colonoscopy. Primary outcome measure is the adenoma detection rate (mean number of adenoma per patient). The investigators will assess and adjust for possible variables that can affect adenoma detection, including withdrawal time and quality of colon preparation. As a secondary outcome of interest the investigators will evaluate a possible learning curve effect among all endoscopists (a minimum of six) new to this method. In addition the investigators will evaluate whether cap assisted endoscopy improves real time prediction of polyp histology.

All patients who present for a colonoscopy and meet inclusion and exclusion criteria will be asked to participate (see inclusion and exclusion criteria). All patients will undergo a regular bowel preparation with polyethylene glycol lavage (based on current standard of care) until clear rectal fluid is evacuated. Patients will be randomized to one of two groups:

1. Standard colonoscopy, or
2. Cap assisted colonoscopy. All colonoscopies will be performed using state of the art high-definition wide angle colonoscopy. The transparent cap, which is attached to the tip of the colonoscope, has a 4mm margin extending beyond the tip of the colonoscope. All patients will undergo a careful endoscopic examination. A timer will provide feedback on the time of insertion and the withdrawal time. Detected polyps will be assessed with standard white light and narrow band imaging to predict polyp histology (adenoma versus no adenoma), then resected and sent for histological evaluation according to standard of care. At least 8 experienced endoscopists at the participating centers will participate. Each endoscopist will perform at least 50 cap assisted colonoscopies as part of the study. Each endoscopist will be asked to complete a survey after 10 and after 50 cap assisted colonoscopies.

Patients will be randomized in blocks of four allocated to each examiner. The order of randomization will be computer generated. Information on randomization will be contained in sealed envelopes assigned to each examiner and individually opened immediately before the procedure after a patient's All participating endoscopist will fill out a questionnaire regarding the use of cap assistance colonoscopy after the initial 10 cap assisted colonoscopies and after at least 50 cap assisted cap colonoscopies. Endoscopists will also undergo a training session with respect to real time polyp diagnosis before study commencement and after each 20 colonoscopies enrollment.

Does Cap Assisted Colonoscopy Improve Detection of Adenomatous Polyps? (CAP Trial)

Mean number of adenomas per patient in each group.

• Adenoma detection rate (ADR), % of patients with at least 1 adenoma

Proportion of patients with advanced adenomas

Proportion of patients with a bowel preparation that was rated as good or excellent (four point scale that distinguishes the bowel prep as poor, fair, good or excellent).

• Time taken for the withdrawal of the colonoscope from the cecum to anus among patients, who did not have any polyps.

• Proportion of patients, for whom intubation of the terminal ileum with the colonoscope was rated as "easy". Intubation could be rated by the endoscopist as "easy", "slightly difficult", "difficult", or "unable to intubate".

Difference in recommended surveillance interval between real time polyp diagnosis and pathological diagnosis among patients with at least one diminutive polyp

Dartmouth-Hitchcock Medical Center

White River Junction Veterans Affairs Medical Center

Standard Colonoscopy

Cap Assisted Colonoscopy

Standard colonoscopy without an attachment cap

A transparent cap will be affixed to tip of the high-definition wide angle colonoscope.

Colonoscopy Cap: 4mm transparent cap (Olympus) mounted to the tip of a colonoscope.

Total

Age, Continuous

Sex: Female, Male

Race and Ethnicity were not collected from any participant.

Race and Ethnicity Not Collected

United States

Region of Enrollment

Indication

Dr. Heiko Pohl

Mean Number of Adenomas

Adenoma Detection Rate

Advanced Adenoma Detection Rate

Quality of Bowel Preparation

Withdrawal Time

Ease of Terminal Ileum Intubation

Real Time Prediction of Polyp Histology

Overall Study

Standard polypectomy snare of adenomatous polyps (included serrated adenomas) from ≤5mm to ≤20mm.

Electrocautery snare resection of sessile colonic polyps

standard polypectomy snare

Heiko Pohl, MD

Colorectal cancer is the second most common cause of cancer death in the US. Colonoscopy is considered the best test colorectal cancer screening. It allows resection of adenomatous polyps (a known cancer precursor) and thus, interrupt the adenoma-carcinoma sequence. Despite the potential benefit of screening colonoscopy recent studies have reported cases of colorectal cancers in a short interval after prior screening or surveillance colonoscopies. One possible cause of such interval cancers may be incomplete resection of adenomatous polyps and hence ongoing growth and cancer development in such lesions. Complete resection may be particularly important for polyps of at least 5mm in size as up 10% of such polyps higher risk lesions as villous adenoma, tubulovillous adenoma, high grade dysplasia, or early carcinoma.

Although adenoma resection of sessile and flat adenomatous polyps between 5 and 20mm is believed to be well standardized data on complete resection of adenomatous tissue are sparse. This may be related to the assumption that using a snare with electro-cautery will successfully remove the polyp and cauterize remaining marginal adenomatous tissue and hence completely remove and or destroy the lesion.

The investigators are interested in examining how often sessile adenomatous polyps between 5 and 20mm are completely removed using standard polypectomy snare. The investigation was also directed at a comparison between complete resection of polyps between 5 and 9mm and 10 and 20mm.

All patients who present for a colonoscopy and meet inclusion and exclusion criteria will be asked to participate, and all patients with resectable polyps will be included. See also inclusion and exclusion criteria.

All patients will have undergone a regular bowel preparation with polyethylene glycol lavage with 4-6 L until clear rectal fluid is evacuated.

Polyp resection will be performed by experienced endoscopists (each with over 500 colonoscopies performed). All polyps between 5 and 20mm will be removed with an electro-cautery snare. Polyp size will be estimated using the snare catheter (2.5mm) or the snare diameter (10x20mm, 15x30mm, 20x20mm) before resection. The endoscopist will grade the difficulty of resection. Following the resection, the endoscopist will closely examine the resection margins. Biopsies will be taken from resection margins: 2 biopsies will be obtained from opposite margins for polyps 5-9mm, and 4 biopsies will be taken for polyps 10-20mm from all four quadrants of the resection margins. In case of assumed incomplete resection this will be documented and further (piecemeal) resections should be done, if this is not feasible, margins can be cauterized according to standard polypectomy resection (e.g. by argon beamer coagulation) after previous biopsy. Only those polyps that are found to be adenomatous polyps will be included in the analysis.

If polyp resection is complicated by bleeding (not self-sustained), no biopsies will be taken and any additional polyps that will be found during the remaining examination will be excluded from analysis. Any bleeding from the margins after polypectomy will be treated by endoscopic injection using diluted epinephrine (1:10.000).

A single research subject may have many eligible polyps. To avoid taking many biopsies, the investigators will not include more than 5 eligible polyps (the first 5 that are detected) per patient in the study.

Laboratory Analysis:

Polyps and biopsies will be sent to the pathology lab of each center. The polyps will be evaluated according to common practice. In addition information regarding resection margins will be provided for each polyp: R0= free of adenomatous tissue, R1=adenomatous tissue detected in the margin. This information is not routinely provided by the pathologist as there is so far no data whether this information is reliable. Only adenomatous polyps will be included in the analysis. Hyperplastic polyps will not be included. Biopsies will only be processed after the diagnosis of an adenomatous polyp was made. Biopsies will be evaluated for presence of adenomatous tissue. The additional impact for the pathology lab includes a) processing of biopsies belonging to the polyp specimens, and b) providing information on polyp margins. The VA pathology lab estimated the financial impact to be low and there will be no financial requests. The pathological diagnosis, including the reading of the biopsies, will become part of the medical record. If biopsies contain adenomatous tissue the patient will be ask to return for a follow-up colonoscopy within 1 year. This is within current standard of care to repeat a colonoscopy to assure complete adenoma resection.

Biopsies will be taken from resection margins: 2 biopsies will be obtained from opposite margins for polyps 5-9mm, and 4 biopsies will be taken for polyps 10-20mm from all four quadrants of the resection margins.

Complete Histologic Resection of Adenomatous Polyps?

Complete Histologic Resection of Adenomatous Polyps? (Complete Adenoma REsection Trial - CARE Trial)

Proportion of incompletely resected adenomatous polyps (5 to 20mm), defined by remaining adenomatous tissue in marginal biopsies after snare resection.

Comparison of the proportion of incompletely resected adenomatous polyps by size (5-9mm versus 10-20mm).

Principal Investigator

Adenomatous polyps (included serrated adenomas) ≤5mm and ≤20mm.

All Adenomatous Polyps

Age, Categorical

Adenomatous polyps (included serrated adenomas) ≥5mm and ≤20mm.

Percent of Incompletely Resected Adenomatous Polyps

Incomplete Adenoma Resection of Small and Large Adenomas

Standard polypectomy snare of adenomatous polyps (included serrated adenomas) from ≥5mm to ≤20mm.

Study title	NCT ID	Conditions	Interventions	Eligibility	Organization
Does Cap Assisted Colonoscopy Improve Detection of Adenomatous Polyps? (CAP Trial)	NCT01935180	Adenomatous Pol...	Colonoscopy Cap	50 Years - 85 Years	White River Junction Veterans Affairs Medical Center
Complete Histologic Resection of Adenomatous Polyps?	NCT01224444	Adenomatous Pol...	standard polype...	40 Years - 85 Years	White River Junction Veterans Affairs Medical Center
Does Cap Assisted Colonoscopy Improve Detection of Adenomatous Polyps? (CAP Trial)	NCT01935180	Adenomatous Pol...	Colonoscopy Cap	50 Years - 85 Years	White River Junction Veterans Affairs Medical Center
Complete Histologic Resection of Adenomatous Polyps?	NCT01224444	Adenomatous Pol...	standard polype...	40 Years - 85 Years	White River Junction Veterans Affairs Medical Center

Spots Global Cancer Trial Database for adenoma resection