下咽頭癌の内視鏡治療

Endoscopic Treatment for Superficial Hypopharyngeal Carcinoma

　食道癌患者の術前術後に内視鏡による系統的スクリーニング検査を行い，17例20病変(47～81歳，男性15例，女性2例)の下咽頭の表在性の癌を発見した．そしてこのうちの13例18病変と前治療後の再発再燃例2例に対して全身麻酔下に内視鏡治療を行った．方法として食道表在癌に行うのと同様の内視鏡的粘膜切除術(EMRC法，np-EEM法)あるいはアルゴンプラズマ凝固法を単独で行うかあるいは併用した．広範囲の4病変は局所の再発再燃を認め，追加治療を要した．また2例では頸部リンパ節再発に対して頸部郭清術が行われた．有害事象として咽頭痛は必発である．その他，誤嚥性肺炎，喉頭浮腫，陰圧肺水腫，遅発性後出血があった．初発で内視鏡治療を行った13例の観察期間は5～75か月(中央値47か月)で，下咽頭癌による死亡例はないが，2例が他臓器癌で死亡し，2例が他病死した．この方法は表在性の下咽頭癌に対するQOLの損なわれない治療法として有望であるが，局所制御効果や安全面での改善が必要であり，集学的治療の一手段として位置づけられる．

　Background : Superficial carcinoma of the hypopharyngeal region is still rare and its therapeutic modality is limited. The aim of this study was to evaluate the feasibility and curability of our endoscopic treatment for these carcinomas.

　Patients and Method : 18 primary lesions in 13 cases and 2 pretreated lesions were treated endoscopically with procedures of EMR (EMRC, np-EEM) or APC, solely or in combination, principally under general anesthesia. All patients had a past history of esophagectomy for esophageal carcinoma.

　Results : In 4 rather extensive lesions, tumors relapsed locally and required additional therapy, such as irradiation or re-treatment. Neck dissection for lymphnode metastases was also carried out in 2 cases. Besides throat pain, which is inevitable, aspiration pneumonia, laryngeal edema, negative pressure pulmonary edema and delayed bleeding were recognized as major adverse events, but no treatment related death. None had disturbances in swallowing or speaking after these treatments. 2 cases died of other carcinomas and 2 died of senile infirmity, but no one died of hypophalyngeal carcinoma.

　Conclusions : Our endoscopic treatment is feasible and a promising modality for superficial carcinoma in the hypopharynx, but further improvements are necessary to increase both safety and the cure rate.