Colonoscopy: New Optical Techniques Are More Efficient And Cost Effective

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Main Category: Colorectal Cancer
Also Included In: Cancer / Oncology
Article Date: 12 Nov 2009 - 0:00 PDT

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An article published Online First and in The Lancet Oncology reports that optical diagnosis is a reliable method of correctly diagnosing small colorectal polyps during routine colonoscopy. This approach could be a more efficient and cost effective alternative to conventional histopathology. Therefore, optical diagnosis could replace formal histopathology for the diagnosis and management of most small polyps in routine clinical practice.

In developed countries, colorectal cancer is the second leading cause of cancer death. However, when detected early it has one of the highest cure rates. Screening programmes for colorectal cancer seek to detect and remove pre-cancerous polyps.

Narrow-band imaging (NBI) is a new optical technology that uses blue light to enhance an image and provide more detail of the lining of the colon including polyps from which most colorectal cancer develops. Using white-light colonoscopy (WLC) and non-magnifying NBI, new optical technologies and chromoendoscopy have improved the ability to diagnose and manage small polyps seen at routine colonoscopy. They dispense the need for formal histopathology which is time consuming, resource intensive, and results in delays in giving patients advice on future cancer risk and screening intervals.

There is indication that these optical technologies could make colonoscopy more efficient and cost effective. In the USA alone, they could potentially save an estimated $95 million each year in histopathology costs.

Ana Ignjatovic and colleagues, from the St Mark's Hospital and the Imperial College London sought to confirm the efficiency, safety, and clinical benefit of these simple and widely available optical techniques. They compared the diagnosis of 363 small colorectal polyps (<10mm) in 130 patients, evaluated by four colonoscopists with different levels of experience. They used both optical diagnosis (WLC, NBI, and chromoendoscopy) and histopathology. The authors investigated as well the accuracy of optical diagnosis at predicting a patient's future cancer risk and advice on screening intervals.

Overall, optical diagnosis accurately identified up to 93 percent of small colorectal polyps (186 of 198 precancerous adenomas and 55 of 62 hyperplastic polyps). This was similar to the overall diagnostic accuracy of standard histopathology. Expert colonoscopists had an accuracy of 95 percent for optical diagnosis and non-expert colonoscopists 87 percent.

Optical diagnosis also enabled 82 of the 130 patients to be given a follow-up colonoscopy date immediately after the procedure. This provided an estimated saving of £6,560 ($10,758) in follow-up clinical appointments. Findings also indicated that advice on screening intervals was the same after histopathology and optical diagnosis for 78 of 82 patients (95 percent).

After estimation, the authors suggest that replacing histopathology with optical diagnosis in routine clinical practice would have resulted in a general saving of 77 percent or £13,343 ($22,000) for the patients in this study.

They explain: "We have shown that optical diagnosis, mainly using white light and non-magnified NBI, is accurate for characterisation of polyps smaller than 10 mm...and seems acceptable across a range of experience."

They write in conclusion: "The short learning curve for NBI…supports early adoption, even outside academic centres. As NBI equipment and experience becomes widespread, optical diagnosis for small colonic polyps could become acceptable standard of care in routine non-academic clinical practice."

"Optical diagnosis of small colorectal polyps at routine colonoscopy (Detect InSpect ChAracterise Resect and Discard; DISCARD trial): a prospective cohort study"
Ana Ignjatovic, James E East, Noriko Suzuki, Margaret Vance, Thomas Guenther, Brian P Saunders
DOI: 10.1016/S1470-2045(09)70329-8
The Lancet Oncology

Written by Stephanie Brunner (B.A.)
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today

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