INTESTINE Vol.20 No.1(2)

特集名 『早期大腸癌』からの20年,『INTESTINE』からの今後20年
題名 大腸LSTの歴史と今後
発刊年月 2016年 01月
著者 藤井 隆広 藤井隆広クリニック
【 要旨 】 1986年頃,工藤によりIIcの存在が明らかになり,1990年には,IIcの類似病変としてLST-NGが発見され,現在ではIIcと同様にLSTも国際的に認知されるに至った.LSTは腺腫癌化説に基づくLST-GとIIc類似のde novo様発育を示すLST-NGの二者に分類され,内視鏡治療指針として後者は一括切除によるESD,前者は分割EMRも許容される病変である.LST-NGは,IIcと同様に発見困難な病変が多く,Japan Polyp Studyの結果からはintervalcancerの最重要病変に位置付けられた.今後,内視鏡の画像強調などの進歩により,LST-NGの発見は容易化していくものと期待される.また,LSTの病態解明に向けて,ESD により一括切除された切除標本を用いたさまざまな研究や,拡大内視鏡による詳細な拡大観察などから発生・発育進展の解明など,われわれ,日本の内視鏡医の将来に向けた使命と感じている.
Theme "Early Colorectal Cancer" and "Intestine", Road to future
Title Laterally spreading tumors (LST) of the colon : Past, present and future
Author Takahiro Fujii Takahiro Fujii Clinic
[ Summary ] In 1986 colonic depressed lesions (Type IIc) were first identified by Kudo et al. Laterally spreading tumors of the non-granular type (LST-NG) were first identified in 1990 as IIc-like lesions. These lesions have come to be as well recognized globally as IIc lesions. LSTs are now classified into the LST granular type (LST-G) which are thought to arise from the "adenoma-carcinoma sequence" and the LST-NG type as IIc-like lesions which are thought to arise de novo. Therapeutically, "en bloc" endoscopic submucosal dissection (ESD) is indicated for the latter, while "piecemeal" endoscopic mucosal resection (EMR) is also indicated for the former. As with colonic IIc lesions, LST-NG lesions are often difficult to identify and have come to be positioned as the most important of all interval cancers, as observed in the Japan Polyp Study (JPS). LST-NGs are expected to lend themselves more readily to accurate diagnosis in the years to come with advances in endoscopic imaging such as en hanced imaging. It remains our current and future mission, as Japanese endoscopists, to contribute to further elucidation of LSTs by conducting wideranging research using "en bloc" specimens obtained with ESD or magnifying endoscopy-based detailed observation of LSTs as they develop, and progress to malignancy.