胃癌EMRの分割切除による完全切除の判定基準―多分割例からみた検討

Possiblity of Complete Resection by Endoscopic Mucosal Resection using the Piecemeal Method

要旨　分割切除の成績を分析し，分割切除標本で完全切除の判定が可能かどうかを中心に検討した．1986年1月から1997年12月までに分割切除した早期胃癌は74例74病変あり，癌の大きさは平均14.7±7mm，対象が大きくなればなるほど多く分割切除される傾向があり，適応拡大により積極的に実施されていた．標本完全回収率は，多分割すればするほど低く，4分割以上の例では50％以下であり，組織構築は困難と考えられた．遺残再発率は2分割切除では10.5％，3分割切除では31.2％，4分割切除では0％，5分割切除では8.3％，6分割切除以上では25％であり，4～5分割切除のほうが遺残再発率が低い傾向がみられた．マーキングの有無による再発率は，施行した場合は8.5％，しない場合は29.6％であり，正確な切除範囲を設定して切除することが重要と考えられた．遺残再発例は，肉眼型ではⅡcが多く，部位ではM領域にあるもので，マーキング未施行例が多かった．症例での標本の病理学的シェーマからは完全切除の判定は不能で，切除後一定期問経過観察し，生検により遺残再発の率を判定していくしか方法はないと考えられた．

　Recently, the size of cancers treated by endoscopic mucosal resection (EMR) has became larger and larger because the piecemeal method has made it possible to resect cancers more than 2 cm in size. To discuss whether such cancers have been resected completely or not, 74 cases with 74 lesions of early gastric cancer removed by EMR using the piecemeal method in our department were analyzed and the results were as follows:

1) During EMR using the piecemeal method the withdrawal of all resected specimens was hard, especially when there were more than 4 pieces.

2) The recurrence rate was 10.5％ of cancers resected in two pieces, 31.2％ in three pieces, 0％ in four pieces, 8.3％ in five pieces, and 25％ in more than 6 pieces, so there was no correlation between recurrence and the number of pieces in which the cancers were resected.

3) On the other hand, the rate of recurrence was 8.5％ of the cases in which the marking procedure around the cancer was carried out before EMR and 29.6 of the cases in which the marking procedure was not carried out.

　It was conpidered that the marking procedure is very important to remove the cancers completly, but the pathological survey of the specimens resected by piecemeal method is unable to determine whether the cancers have been resected completely or no.