大腸pSM癌に対する内視鏡治療根治基準の拡大―根治基準拡大に向けて解決すべき病理学的問題点─SM浸潤距離

Pathologic Problems for Expansion of Concept of the Curative Condition in Cases with Submucosal Invasive Carcinoma Resected Endoscopically: with Special Reference to the Method for Measuring Depth of SM Invasion

要旨　「大腸癌治療ガイドライン2009年版」による内視鏡的摘除pSM癌の治療方針では，“追加腸切除考慮群”のリンパ節転移リスクが十分に絞り込まれておらず，その層別化が必要である．SM浸潤距離因子（1,000μm以上）のみが陽性で“追加腸切除考慮群”とされる病変のリンパ節転移率は5.8％であり，それらの中には内視鏡的摘除で根治が期待される病変が含まれている可能性がある．SM浸潤距離に関してどの程度の値まで根治基準の拡大が可能か，が今後の課題である．そのためには，SM浸潤距離測定の診断者による均霑化と，有茎性SM癌のSM浸潤距離測定法についての再検討が必要と考えられる．

　It is required in the JSCCR（Japanese society for cancer of the colon and rectum）guidelines 2009 to establish the stratification system of risk of lymph node metastasis for a group of pSM colorectal carcinomas which are indicated for requiring consideration of additional intestinal resection after endoscopic treatment. The rate of lymph node metastasis for pSM carcinomas which would be indicated for additional treatment by fulfilling one of the indication criteria alone, SM depth of more than 1,000μm, is estimated to be only 5.8％. Some of those carcinomas have the possibility to be cured by endoscopic treatment alone. To elucidate this issue, it is thought that the standardization of the method for measuring depth of SM invasion and re-evaluation of the method applicable for pedunculated type SM carcinomas are requiring.