Usefulness of NBI magnifying endoscopy for diagnosis of early cancer in colorectal lesions <10mm

Abstract

Endoscopic diagnosis for identifying early cancer in small colon polyps is essential to select appropriate endoscopic resection method. This study aims to assess the clinical usefulness of NBI magnifying endoscopy for diagnosis of early cancer in colorectal lesions <10mm. We retrospectively analyzed all colorectal lesions <10mm which were diagnosed by NBI magnifying endoscopy according to The Japan Narrow-band imaging Expert Team (JNET) classification and resected endoscopically from March 2014 to September 2016. 797 lesions in 394 patients were analyzed. Pathologically, 696 (87.2%) lesions were adenoma, 10 (1.3%) and 2 (0.2%) lesions were Tis and T1 cancer, respectively, counting 1.5% cancer-carrying rate. 753 lesions diagnosed as JNET Type2A harbored only 4 cancers (0.5%). In sharp contrast, 12 lesions diagnosed as JNET Type2B comprised 7 cancers (58.3%) and one lesion diagnosed as JNET Type3 was T1b cancer, which indicates Type2B/3 are reliable findings for diagnosis of early cancer. NBI magnifying endoscopy according to JNET classification is a useful modality for diagnosis of early cancer in colorectal lesions <10mm.