未分化型早期胃癌に対するESDの治療成績と長期予後

Curability and Long-term Outcome of ESD for Early Undifferentiated-type Gastric Cancer

要旨　12か月以上経過観察しえた未分化型早期胃癌59例60病変を対象とし，内視鏡治療適応別に一括切除率，完全一括摘除率，不完全切除の要因，予後について検討した．一括切除率は，相対適応病変91.2％，適応外病変80.8％，完全一括摘除率は，相対適応病変91.2％，適応外病変65.4％で，適応外病変の完全一括摘除率は相対適応病変に比べて有意に低かった．不完全摘除例は12病変であった．側方断端陽性（不明）を1例，深部断端陽性を3例に認めた．分割切除は6例で，その要因は術中出血の止血困難3例，ULに伴う手技的困難2例，穿孔3例であった（重複あり）．中止例は2例で，いずれもESD導入初期の術中出血に対する止血困難例であった．予後に関しては，相対適応病変33例および適応外病変のうち完全一括摘除された8例と不完全摘除3例の合計44例が外科的追加切除なく経過観察中（平均観察期間42.3±16.8か月）であるが，現在まで局所・転移再発および原病死例を認めなかった．

　Endoscopic submucosal dissection（ESD）makes it possible to perform complete resection not only of lesions larger than 20 mm but also of those with ulceration, regardless of location. We analyzed 60 cases of undifferentiated-type early gastric cancer resected by ESD in our institution. Complete en bloc resection rate and perforation rate of undifferentiated gastric cancer with the expanded indication（intramucosal cancer smaller than 20 mm in diameter without ulceration and lymphatic / vessel involvement）was 91.1％ and 9.1％. Neither local recurrence nor lymph-node metastasis were observed after complete resection（31 cases）and incomplete resection（2 cases）for these lesions. Our results showed that the expanded indication for ESD in cases of undifferentiated-type gastric cancer appears acceptable.