表在型食道胃接合部癌の治療戦略─内視鏡治療の立場から

Short- and Long-term Outcomes of ESD（Endoscopic Submucosal Dissection）for Superficial Esophagogastric Junction Cancer

要旨●ESDを施行した表在型食道胃接合部癌（Siewert分類Type II）76例76病変の治療成績を検討した．ESDの適応，治癒切除基準は胃癌治療ガイドラインに従った．一括切除割合，一括完全切除割合，治癒切除割合はそれぞれ100％，82.9％，65.8％であった．後出血割合は0％，穿孔割合は2.6％であり，術後狭窄割合は9.2％であった．観察期間中央値は6.4年で，治癒切除で経過観察された49例に再発，原病死は認めず，5年無再発生存率，5年全生存率，5年疾患特異的生存率は100％，97.8％，100％であった．食道胃接合部癌に対するESDは技術的に妥当であること，長期予後の観点から内視鏡治療の治癒切除判定は胃癌に準じて行える可能性が示唆された．しかしながら，症例数が少なくリンパ節転移リスクの検討やESDの長期成績については，さらなるエビデンスの構築が必須である．

　This retrospective study investigated short- and long-term outcomes of ESD（endoscopic submucosal dissection）for superficial EGJ（esophagogastric junction）cancer. The clinical indication of ESD and the criteria of curative resection were based on the Japanese gastric cancer treatment guidelines. In total, 78 patients with 76 superficial EGJ cancers were included in this study. The en bloc resection rate, R0 resection rate, and curative resection rate were 100%, 82.8%, and 65.8%, respectively. Delayed bleeding, perforation, and post-ESD stricture occurred in 0%, 2.6%, and 9.8% of the cases, respectively ; however, all complications could be managed conservatively. None of the 49 patients who underwent curative resection, and who were followed up without any additional surgeries, developed any recurrence during a median follow-up period of 6.4 years（0-14.5）. The 5-year recurrence-free survival rate, overall survival rate, and disease-specific survival rate were 100%, 97.8%, and 100%, respectively. This study showed the clinical feasibility and favorable long-term outcomes of ESD for superficial EGJ cancers. Further multicenter prospective studies are warranted to confirm our results and provide clinical evidences.