中・下咽頭表在癌の内視鏡治療―EMRの立場から

Endoscopic Therapy for Superficial Cancers in the Oropharynx and Hypopharynx: EMR（Endoscopic Mucosal Resection）

要旨　食道表在癌に対する内視鏡治療が普及してきたなか，field cancerizationの概念から頭頸部の観察も必要であるという意識が高まってきたことによって，中・下咽頭に表在性の癌を指摘できるようになってきた．これまでは，中・下咽頭領域の早期癌に対する治療は部分切除もしくは放射線療法が主体であったが，近年，機能を温存し局所治療を目的とした内視鏡治療が新しい治療法として注目されてきている．しかし，内視鏡治療を行った場合，手技による合併症対策や，リンパ節転移の危険因子，追加治療の要否など，今後検討しなくてはならない課題も多い．現在多施設において中・下咽頭表在癌に対する内視鏡治療が行われつつあり，症例の積み重ねによってこれらの問題が解決され，内視鏡治療がこの領域の治療選択の1つとして確立されることが期待される．

　Endoscopic therapy has become a common treatment for superficial esophageal cancer. From the perspective of field cancerization, it is now widely regarded that additional observation of the head and neck region is necessary, leading to more cases in which superficial carcinoma of the oro-and hypopharynx are diagnosed. While partial resection and radiation therapy is the currently accepted standard treatments for early-stage oro-and hypopharyngeal cancer, function-preserving local endoscopic therapy has been considered as an alternative treatment. However, endoscopic therapy involves certain issues which must be addressed, such as complications due to the procedure, risk factors for lymph node metastasis, requirement of additional treatment, etc. The endoscopic treatment is performed in many institutions, and the issues may be resolved through accumulation of case experience, resulting in establishment of the therapy as one of the standard treatments of superficial oro-and hypopharyngeal cancer.