家族性大腸腺腫症における十二指腸乳頭部病変の取り扱い

Management of Periampullary Lesions in Patients with Familial Adenomatous Polyposis

要旨　家族性大腸腺腫症の十二指腸乳頭部癌の相対危険度は高く，予防的大腸全摘後の予後因子として十二指腸病変の取り扱いが課題となっている．上部消化管内視鏡によるサーベイランスは重要で，特に乳頭部周囲の観察には注意を要し，Spigelman's stage IVとなる高度の十二指腸腺腫症や増大傾向のある乳頭部腺腫は癌化の危険度が高いことから予防的切除の対象となる．また，内視鏡的粘膜切除やアルゴンプラスマ凝固療法は有用と思われ，その適応や施行の拡大が望まれる．内視鏡によるサーベイランスにも限度があり，分子生物学的アプローチでは遺伝子解析などによる癌化しやすい亜群分類の研究が期待されている．手術療法では縮小手術として幽門温存，または膵頭温存十二指腸切除が選択される機会が増えると思われる．化学予防においては選択的COX-2阻害剤の有効性が認められ，今後の新たな展開が予想される．

　As the relative risk of periampullary carcinoma is high in patients with familial adenomatous polyposis (FAP), the management of periampullary lesions has been studied as the prognostic factor to treat patients with FAP after prophylactic total colectomy. Surveillance with gastroduodenal endoscopy is important, and careful observation around the papilla of Vater is especially necessary. Severe duodenal polyposis like Spigelman's stage IV and developing ampullary adenomas have high risk of canceration and are indications for prophylactic duodenal surgery. Endoscopic mucosal resection and Argon plasma coagulation may be useful, and their indication and implementation will be further developed. Endoscopic surveillance had limitations for early diagnosis of duodenal cancer, so further study using the molecular-biological approach such as genetic analysis for classification of subgroups with high risk of duodenal cancer is called for. In the future, pylorus-preserving pancreaticoduodenectomy and pancreas-preserving duodenectomy may be the main methods selected for surgical treatment. COX-2 inhibitors have recently been shown to be useful and further development of chemoprevention therapy is looked forward to.

　1) Division of Surgery, Yokohama City Citizen's Hospital, Yokohama, Japan