多発食道癌とEMR

Multiple Early Esophageal Cancer Treated with Endoscopic Mucosal Resection (EMR)

要旨　発生して間もない初期の病巣が存在し，多発か単発かが明瞭に判定でき，かつ，長期にわたり異時性多発を検討しうるEMR施行早期食道癌349例を対象に多発癌につき検討した．多発癌は69例（19.8％），同時性51例，異時性28例であった．異形成を加えると多発例85例（24.4％）となった．同時性多発癌では2病巣が70.6％を占め，1病巣を除き0-Ⅱ型であり，m₁・m₂が90.2％を占めた．異時性多発癌は全EMRの8％に相当し，平均2年半で発生していた．1次癌が多発であったものが単発であったものより有意に異時多発が多かった．生検やEMRで異形成と病理診断されたものでも注意して経過観察すべきである．“癌は多発が原則，重複癌も同様”と考えるべきで，1つ癌が発見されたら厳重な経過観察が重要である．

　Seventy-two multiple primary esophageal cancers were analyzed from 349 cases of early esophageal cancer treated by endoscopic mucosal resection. In those patients, the differentiation between solitary and multiple lesions was possible, and asynchronous multiple lesions could be detected by long-term follow up. Multiple cancers consisted of 51 cases of synchronous and 28 cases of asynchronous ones. Multiple cases amounted to 85 cases (24.4％) when dysplasia is counted as a cancerous lesion. The characteristics of synchronous multiple cancers were: 1) The most frequent number of lesions was 2 (70.6％). 2) The most frequent type was 0-Ⅱ type, which was mostly m₁ or m₂ in depth (90.2％). The characteristics of the asynchronous multiple cancers were: 1) Asynchronous cancers occupied 8％ of all the endoscopic mucosal resection cases. 2) The mean interval between the first lesion and the appearance of the second lesion was 2 and a half years. The multiple primary lesions had a significantly greater number of asynchronous lesions than the solitary primary lesions. Careful follow-up is required even in the dysplasia cases diagnosed by biopsy or endoscopic mucosal resection. A cancer is generally developing in a multiple manner, so the possibility of double cancers should be always kept in mind as a reason for follow-up after detection of a sole cancer.