大腸SM癌の浸潤距離を実測することの意義と問題点

Measuring the Depth of Invasion in Submucosal（SM）Cancer of the Colon and Rectum Based on the Guidelines for the Treatment of Colon and Rectal Cancer and Its Supplementary Notes

要旨　大腸SM癌の浸潤距離の測定法について「大腸癌治療ガイドライン」をもとに概説した．併せて均てん化に向けていくつかの修正点を指摘し，補足・改良点に言及した．SM癌の細分類はどのような方法をとっても例外は生じる．したがって，その目的は SM癌の分類の是非を問うものではなく，いかに標準化したリンパ節転移率を表示できるかである．将来的には遺伝子異常，癌環境因子あるいはエピジェネティックな因子からの診断・治療選択も考えられるが，現状では内視鏡治療標本の水平断端，垂直断端，浸潤距離，脈管侵襲，簇出の診断精度を上げることが最も重要であることを強調した．その中でも，有茎性とそれ以外を内視鏡的に診断・治療することの重要性と， head invasionを広く有茎性病変に適応できる方向性を示す必要性を論じた．

　We outline the method for measuring the depth of invasion in submucosal（SM）cancer of the colon and rectum based on the Guidelines for the Treatment of Colon and Rectal Cancer. Additionally, we indicate several points to be corrected and refer to supplementary notes and improvements for making it possible for gastrointestinal endoscopists and surgeons to use the method. Any subclassification of SM cancer has exceptional cases. So, we aim not to compete in the classification of SM cancer but to discover a standardized rate of lymph node metastasis. In the future, diagnosis and the selection of endoscopic treatment may be made based on genetic abnormalities, or epigenetic factors. However, we emphasize that it is now most important to improve the diagnostic accuracy of the horizontal margin（pHM）, vertical margin（pVM）, depth of invasion（1,000μm, or not）, invasion of vessels, and budding/sprouting of samples obtained during endoscopic treatment. Particularly we discuss the importance of assessing whether the lesion is pedunculated in order to treat it endoscopically and the need to give directions to widely adapt head invasion in pedunculated lesions.