Clinical Trial: Complete Histologic Resection of Adenomatous Polyps?

Study Status: Completed
Recruit Status: Completed
Study Type: Observational

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

Brief Summary:

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.


Detailed Summary:

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 m
Sponsor: White River Junction VAMC

Current Primary Outcome: Percent of Incompletely Resected Adenomatous Polyps [ Time Frame: 1 year ]

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


Original Primary Outcome: Primary Endpoint [ Time Frame: 1 year ]

• Proportion of remaining adenomatous tissue after adenoma resection of all sessile polyps between 5 and 20mm.


Current Secondary Outcome: Incomplete Adenoma Resection of Small and Large Adenomas [ Time Frame: 1 year ]

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


Original Secondary Outcome: Secondary Endpoint [ Time Frame: 1 year ]

• Comparison of the proportion of completely resected sessile adenomatous polyps by size (5-9mm versus 10-15mm)


Information By: White River Junction VAMC

Dates:
Date Received: October 19, 2010
Date Started: May 2008
Date Completion:
Last Updated: December 30, 2014
Last Verified: December 2014