NICE分類からJNET分類へ

Development of the Two Universal NBI Classifications ; NICE Classification and JNET Classification

要旨●NICE分類はType 1〔過形成性ポリープ（SSPを含む）〕，Type 2（腺腫〜SM軽度浸潤癌），Type 3（SM深部浸潤癌）に分かれたNBIの非拡大分類として2009年に提唱され現在も海外で広く使用されている．一方，JNET分類は日本の既存の拡大NBI分類（佐野分類・広島分類・昭和分類・慈恵分類）を統一した分類であり，NICE分類を基調として科学的根拠に基づき2014年に作成された．JNET分類はNICE分類同様Type 1〜3に分類されるが，Type 2はType 2A〔腺腫：ポリペクトミー（分割切除許容）〕とType 2B〔粘膜内癌・SM軽度浸潤癌：EMR・ESD（一括切除必要）〕の2群に亜分類され，NICE分類をより進化させた分類である．

　Established in 2009, the NICE classification（NBI international colorectal endoscopic classification）is a simple, globally utilized non-magnified NBI classification comprising of three categories, Type 1：hyperplastic polyps, including SSPs, Type 2：adenoma-superficial submucosal adenocarcinoma and Type 3：Deep submucosal invasive cancer. The JNET classification（Japan NBI expert classification）was developed in 2014 to unify the four co-existing, magnified NBI classifications（Sano, Hiroshima, Showa and Jikei classifications）to three categories. Type 1 and 3 in the JNET and NICE classifications both correspond to hyperplastic polyps and deep submucosal invasive cancer respectively. In contrast to the NICE classification, Type 2 in the JNET classification was subdivided into Type 2A：adenoma, polypectomy with acceptable piecemeal resection and Type 2B：high grade dysplasia-superficial submucosal adenocarcinoma, EMR or ESD with en bloc resection is necessary. Although the methodology adopted to create this new classification was similar to that adopted to create the NICE classification, JNET classification has evolved further and allows endoscopists to select an appropriate treatment strategy for treating colorectal lesions.