大腸sm癌の内視鏡的治療の適応

Indications for Colonoscopic Treatment for Colorectal Carcinomas with Invasion in the Submucosa

要旨　大腸sm癌の内視鏡的治療の適応を明らかにするために，自験例125例の分析を行った．その結果，脈管侵襲陽性，病変全体の組織像が中～低分化腺癌・粘液癌，先進部の中～低分化傾向，の3つの因子が有意にリンパ節転移と関連していた．sm₂であっても，上記のrisk factorを有さない病変にはリンパ節転移はなかった．sm₁とsm₂の分類基準が施設によって一定しないという問題点もあるが，sm₂と判定しても上記risk factorを有さない病変に対しては，内視鏡的治療のみでも十分な治療となる可能性も考えられた．

　One hundred and twenty-five colorectal carcinomas with submucosal invasion were studied to clarify the indication for colonoscopic treatment. The significant risk factors for lymph node metastasis were, lymphatic channel invasion, moderate to poor differentiation or mucinous carcinoma on histology, moderate to poor differentiation in the margin of invasion. Level 2 in invasion of the submucosa (sm₂) itself was not a risk factor for lymph node metastasis. None of the lesions with sm₂ invasion lacking these risk factors for lymph node metastasis showed lymph node metastasis. Although the criteria for level 2 invasion (sm₂) vary among reports, when there are no such risk factors as those mentioned above, the lesions with level 2 invasion in the submucosa (sm₂) might be safely treated with colonoscopic removal.