Colonoscopic Cancer Surveillance in Inflammatory Bowel Disease: What's New Beyond Random Biopsy?
Colonoscopy based colitis surveillance is widely accepted to try to prevent development of and ensure early detection of colitis-associated colorectal cancer. Traditionally this has been performed with quadrantic random biopsies throughout the colon. Chromoendoscopy "dye-spray" with targeted biopsies only has been shown to increase dysplasia detection 4 to 5 fold on a per lesion basis. It has therefore been suggested that random biopsies should be abandoned as they do not increase dysplasia detection nor change patient clinical course. Recent British guidelines for colitis surveillance have strongly endorsed chromoendoscopy. This short review summarizes current international guidelines and looks at how to optimize white light colonoscopy in colitis considering: bowel preparation, withdrawal time, high definition, and structure enhancement. Data for advanced imaging techniques are reviewed including positive evidence in favor of chromoendoscopy, and limited data suggesting autofluoresence imaging may be promising. Narrow band imaging does not increase dysplasia detection in colitis. Confocal endomicroscopy might potentially reduce biopsies beyond that of chromoendoscopy but does not offer a clear detection advantage. Pan-colonic chromoendoscopy with targeted biopsies increases dysplasia detection and is the standard of care in the United Kingdom. It is likely that the use of chromoendoscopy for colitis surveillance will become widely accepted internationally.