Narrow band imaging for colonoscopic surveillance in hereditary non-polyposis colorectal cancer

Background:Colonoscopic surveillance for hereditary non-polyposis colorectal cancer (HNPCC) reduces death rates, but early interval cancers still occur, probably due to missed small, aggressive adenomas. Narrow band imaging (NBI), a novel endoscopic technology, highlights superficial mucosal capillaries and improves contrast for adenomas. This study examined whether a second pass with NBI in the proximal colon helped detect additional adenomas in patients with HNPCC.Methods:62 patients from HNPCC families (Amsterdam II or genetic criteria) attending for colonoscopic surveillance were examined twice from caecum to sigmoid–descending junction, first with high definition white light and then a second pass with NBI in a back-to-back fashion. All polyps detected were removed for histopathological analysis.Results:At least one adenoma in the proximal colon was detected during the initial white light pass in 17/62 (27%). NBI detected additional adenomas in 17/62 (27%). 26/62 (42%) patients had at least one adenoma detected after both white light and NBI; absolute difference 15% (95% CI 4–25%), p = 0.004 versus white light alone. The total number of adenomas increased from 25 before NBI to 46 after NBI examination, p