Cutting-edge technologies signify a new era for colorectal cancer screening

05/12/05

CHICAGO, IL (May 17, 2005) – This year, more than 145,000 people will be diagnosed with colorectal cancer (CRC). Despite its high incidence, CRC is one of the most preventable and treatable forms of cancer when found early. Studies presented today at Digestive Disease Week® 2005 (DDW) explore three novel technologies for colorectal cancer screening that provide innovative techniques that could potentially overcome limitations of existing screening methods. "Colonoscopy is currently the gold standard for detection of colorectal cancer, but is not without its limitations," said Robert Bresalier, M.D., of the University of Texas MD Anderson Cancer Center. "The findings presented today could lead to significant advancements and an overall improvement in the diagnostic efficacy of colon screening."

Onco-LIFE Fluorescence Imaging During Colonoscopy Assists in the Differentiation Of Adenomatous and Hyperplastic Polyps and Improves the Detection Rate Of Dysplastic Lesions in the Colon (Abstract 154)

Researchers are continually looking for new technologies and imaging techniques to enhance the accuracy of CRC screening. In this study by a team of researchers at the University of Toronto, a new fluorescent technology shows significant benefit in improving the diagnostic capability of colonoscopy.

The new technology, "Onco-LIFE" (Light-Induced Fluorescence Endoscopy), uses blue light with combined fluorescence and reflectant cameras to illuminate and obtain real-time color images during colonoscopy procedures. The light reflected in the colon is different when tumors are present, so the color of the images changes to aid in the detection of tumors when used in conjuction with conventional white light imaging.

This study evaluated the device's efficacy in reducing the polyp miss rate and its ability to discriminate between types of tumors. Results suggest that the use of Onco-LIFE as an adjunct to conventional colonoscopy enhances the diagnostic capability of the procedure by increasing the detection of smaller tumors and improves the accuracy of tumor classification at colonoscopy.

A prospective, single-arm, single-center study enrolled patients undergoing colonoscopy for colorectal cancer screening or monitoring. The researchers examined the colon using white light (WL) followed by fluorescence light (FL). Of 285 evaluable biopsies, a total of 123 lesions were found in 44 patients (120 adenomas, two carcinomas and one carcinoid tumor). FL examination identified 19 adenomas (including diminuitive and flat adenomas) that were missed at WL examination, suggesting an increased detection rate of 18.3 percent (19 of 104 adenomas). Accuracy of endoscopic diagnosis for atypical lesions improved from 57 to 83 percent and hyperplastic lesions from 59 to 70 percent with the use of both white and fluorescent light.

"Colonoscopy remains the best way to detect colon cancer. However, we feel that fluorescent technology effectively enhances this standard diagnostic procedure and provides a useful tool for achieving greater accuracy," said Norman Marcon, M.D. of The University of Toronto and senior author of the study. "The results of this trial are promising and warrant further evaluation in larger clinical trials."

Aer-O-Scope: Self-Propelling Self-Navigating Skill-Independent Colonoscopy; a New Era in Screening Colonoscopy (Abstract 90)

The colonoscopy screening procedure has been the subject of debate in the field of gastroenterology due to drawbacks in training, compliance and demand. However, findings presented today show that an innovative technology may bring about a new era in CRC screening. Researchers at the Tel-Aviv Sourasky Medical Center evaluated the safety and efficacy of a self-propelling, self-navigating, skill-independent, miniature colon screening device called an Aer-O-Scope. The device is being developed by GI View Ltd., a start-up company in Israel. The team evaluated the technology for the duration of the procedure, the average advancement (in centimeters) of the device, mucosal damage and achieved success in each major endpoint.

Based on the similarities in size and dimension of the human colon, the team used 10 young, female pigs in this study and conducted the procedure twice in each pig. The procedure ranged from 11 to 29 minutes (an average of 16.5 min). The average advancement and pull back duration were 10 minutes (range of 2-19 min) and 3.4 minutes (range of 2-9 min), respectively. In all cases, the Aer-O-Scope advanced at least 102 cm (mean 143 cm), and in 12 cases it advanced as far as possible (155 cm). In the eight cases where the Aer-O-Scope did not fully advance, the colon had inadequate bowel preparation.

Following the Aer-O-Scope procedure, a gastroenterologist performed a standard colonoscopy to detect perforation, erosion and mucosal damage. No significant adverse events were detected. All animals were in good condition at 24 hours and seven days post-procedure.

"Preliminary studies which supplied the proof of concept in humans as well as the study presented here suggest that this technology could provide a reliable, less invasive, sedation-free and more easily administered screening option for colon cancer," said Nadir Arber, M.D. of the Tel-Aviv Sourasky Medical Center and lead author of the study. "Although we have more work to do before this device is widely utilized in humans, it is an exciting prospect for patients and physicians alike."

Evaluation of a New Partially-Automated, Potentially Sedationless Colonoscope (Abstract 562)

A concern regarding colonoscopy screening is the discomfort associated with the procedure for the patient. A new type of colonoscopy system (the Navigator Endoscopy System) developed by Silicon Valley-based NeoGuide Systems may offer patients an effective, painless and potentially sedationless option.

Unlike conventional endoscopes, the Navigator colonoscope features multiple bendable segments in addition to a physician-controlled distal tip. The System continually monitors the depth and position of the tip, and uses proprietary computer algorithms to build a real-time, three-dimensional map of the patient's colon. The System then directs each of the segments to follow the shape of the colon, as identified by the physician. Because the System is designed to follow the natural shape of the colon, less force is applied to the colon wall. This could potentially eliminate or significantly reduce the incidence of looping, which is responsible for the majority of patient pain in colonoscopy. The System also offers advanced capabilities and features, including the display of a real-time 3-D map of the colon and the ability for physicians to mark the location of polyps on this map.

Researchers conducted initial testing on the scope's force via an inanimate colon model instrumented with four force transducers. Transducers were located at four points: proximal to the simulated anus, the proximal and distal ends of the sigmoid flexure and the splenic flexure. The team measured reductions in average force measurements (pounds) using both a conventional colonoscope (CS) and the study device (SD) and found statistically significant reductions at each of the last three points (CS/SD: 1.2/0.9, 2.5/1.3, 0.7/0.2 and 0.4/0.2).

Secondary studies in animal colons demonstrated the safety of the Navigator Endoscopy System, with no tissue damage or perforations associated with the System.

"Looping is the principle reason that many colonoscopy procedures are painful, time consuming and difficult," said Amir Belson, M.D., president and co-founder of NeoGuide Systems Inc. "We believe that by addressing this, the Navigator Endoscopy System has the potential to significantly increase the number of colonoscopies that endoscopists are able to perform, which will be particularly important as the demand for the procedure continues to grow."

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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