口腔表在癌の内視鏡診断

Endoscopic Diagnosis of Superficial Oral Cancer

要旨●世界における口腔癌の罹患数，死亡数は喉頭癌・中咽頭癌・下咽頭癌よりも多い．また，field cancerization現象として食道癌や頭頸部癌の治療前後に発生することをしばしば経験する．JEC試験は330例の食道癌内視鏡的切除例を対象に6か月ごとの上部消化管内視鏡検査と12か月ごとの耳鼻咽喉科診察を継続しながら経過観察する前向きコホート研究である．2年累積異時性頭頸部癌発生率は3.7%であり，耳鼻咽喉科診察により1例の口腔癌（硬口蓋）が表在癌で発見された．112例の食道癌患者を対象に頭頸部領域をNBI拡大内視鏡で観察する前向き研究では，3例の口腔癌（舌2，硬口蓋1）が表在癌で発見された．口腔癌の予後やQOL改善に貢献するためには，消化器内視鏡を用いた適切な口腔観察方法や早期診断を目的としたサーベイランス方法を確立する必要がある．

　Oral cancer has higher incidence and mortality rates than laryngeal, oropharyngeal, and hypopharyngeal cancers. It often occurs before and after esophageal or head and neck cancer treatment as a field cancerization phenomenon. The Japan Esophageal Cohort study is a prospective cohort study that enrolls patients with esophageal cancer after endoscopic resection. Esophageal or head and neck endoscopic examinations were repeated every 6 months. Local examinations to detect head and neck cancer by an otolaryngologist were repeated every 12 months. The 2-year cumulative incidence of metachronous head and neck cancer was 3.7%. An otolaryngologist detected one patient with superficial head and neck cancer originating from the hard palate. Narrow-band imaging magnifying endoscopy of 112 patients with esophageal cancer undergoing head and neck screening in a prospective study revealed two patients with superficial cancers on the tongue and one on the hard palate. Appropriate endoscopic oral cavity observation and surveillance should be established for early detection to help improve the prognosis and quality of life in patients with oral cancer.