背景因子からみた異時性多発食道癌の長期経過―多発ヨード不染帯との関連を中心に

Metachronous Multiple Cancers in the Esophagus and Pharynx and their Prognosis. Association with Multiple Lugol-voiding Lesions in the Background Mucosa

要旨　EMRを施行した早期食道癌116症例165病変を対象に，食道内多発癌症例の臨床的特徴と治療成績，食道粘膜の多発ヨード不染帯（multiple Lugol-voiding lesions;multiple LVL）と食道内多発癌および頭頸部重複癌の関連について検討した．同時性・異時性食道内多発癌の発生は計24例（20.7％）に認めた．また，2病変の場合が11例（45.8％）で，3病変以上をもつ場合が13例（54.2％）と半数を超えていた．多変量解析では，multiple LVLが食道内多発癌発生の独立した危険因子（オッズ比3.5，95％信頼区間1.2～10.1，p＝0.02）であった．multiple LVLは異時性食道内多発癌の発生，3病変以上の多発癌，頭頸部重複癌の存在に関連していた．また，multiple LVLを伴う症例（n＝38）の3年累積多発癌発生率は41.9％で，伴わない症例（n＝78）の13.2％と比較して有意に高かった（p＜0.01）．したがって，multiple LVLを伴う場合，食道内多発癌・頭頸部重複癌発生のリスクを考慮し，食道および頭頸部を厳重に経過観察することが必要である．

　Using a consecutive 116 patients with esophageal squamous cell carcinoma who underwent EMR, we investigated the clinical characteristics of the patients with multiple cancer and their prognosis, and also the association with head and neck cancers. Among them, 24 patients (20.7％) developed multiple intra-esophageal squamous cell carcinomas;9 developed synchronous multiple cancers and 9 were metachronous and the remaining 6 were both. Eleven patients had double lesions and 13 had more than triple lesions. The presence of multiple Lugol-voiding lesions (multiple LVL) was closely associated with the development of multiple intra-esophageal squamous cell carcinomas (odds ratio 3.5, 95％ CI 1.2～10.1, p＝0.02). And it was also associated with the development of metachronous multiple cancers, multiple cancers with more than triple lesions, and head and neck cancers. The cumulative rates of the development of multiple intra-esophageal squamous cell carcinomas after 3 years in patients with multiple LVL and those without multiple LVL were 41.9％ and 13.2％ (p＜0.01), respectively. To achieve complete treatment for early esophageal cancer by EMR, we should pay special attention to the detection of multiple intra-esophageal squamous cell carcinomas and head and neck cancers among the patients with multiple LVL.