食道癌の発育進展―内視鏡を中心に

Growth and Development of Esophageal Cancer－Endoscopical Viewpoint

要旨　診断学の進歩により表在型食道癌の報告例が多くなってきた．しかし，いまだ切除例の8割近くは進行癌である．本稿では食道癌のnatural historyを逆追跡できた症例から食道癌の発育進展について考察した．検索対象は3か月以上の間の経過観察ができた14例である．食道造影写真から検討した食道癌のdoubling timeは切除時，表在癌であった症例（A群）で5.5±1.7か月，初回時は表在癌と推定されたが経過観察の問に粘膜下層を越えた進行癌に発育した症例（B群）では4.6±2.9か月であった．一方，初回時に既に進行癌であった症例（C群）では3.4±3.4か月であり，癌の深達度が深くなるにつれ，doubling timeは速くなる傾向がみられた．内視鏡形態からはA群ではⅡc内の表面の隆起，顆粒成分が明瞭になり，Ⅱbも陥凹が明らかになりⅡcへと変化した．また，Ⅱaはそのまま大きくなり，Ⅰ型に変わっていた．B群ではIIcが1型と3型に1例ずつ変化した．C群では内視鏡型は変化しなかったが，隆起の増大とそれにつれて狭窄が増強した．

　Because of improvement of diagnostic methods, superficial type of esophageal cancer has often been reported, but even now, almost 80％ of the resected cases are still shown to be cases of advanced cancer. We studied growth and development of esophageal cancer by tracing its progression retrospectively. Materials for this study were 14 patients whom we could observe for more than three month. As to the doubling time of esophageal cancer, it was 5.5±1.7 months in group A. At operation the cancers in this group were found to be superficial. They were identified through barium meal study. The doubling time was 4.6±2.9 months in group B. Cancers in this group were assumed to be superficial at the first examination, but changed to advanced cancer during the period of observation. Doubling time was 3.4±3.4 months in group C. Cancers in this group were assumed to be advanced cancer at the first examination. There is a tendency for doubling time to get shorter as the invasion deepens. According to the endoscopical features, in group A, protrusion and granular components in IIc area, and depression in IIb become conspicuous. In group B, one lesion of type IIa changed to type I, IIc changed to type 1, another to type 3. In group C, there was no change in endoscopical type but the size was naturally enlarged by progressive luminal stenosis.