胃癌内視鏡的切除後の遺残・多発癌発見を目指したサーベイランス

Surveillance after Endoscopic Resection of Early Gastric Cancer

要旨　胃癌内視鏡的切除を行った190例に追跡を実施し，18例（9.5％）に遺残を見い出した．遺残診断までの平均期間は208日であり，上部領域では高率に発見された（p＜0.01）．累積遺残発見率は1年8.8％，2年9.7％，3年12.4％と上昇したが，3年以後にはなかった．また，14例（7.4％）に合計21個の多発癌巣を見い出した．多発診断までの平均期間は768日であった．初回癌巣の肉眼型と同じもの8個，異なったもの13個であり，近傍発生14個，離れたもの7個であった．累積多発癌発見率は1年5.6％から7年26.9％まで，ほぼ一様の傾きで上昇した．内視鏡的切除後のサーベイランスとしては，一括完全切除以外では1年目に数回，白色瘢痕化する3年目までは年1回の切除部位生検を含めた内視鏡追跡を実施する．多発癌診断のためには1年間隔に，初回癌巣近傍を入念に，胃全体を観察し，追跡期間は可能な限り長くすべきである．

　Since the advent of endoscopic submucosal dissection, the indication for endoscopic mucosectomy has been expanded to include half of the differentiated early gastric cancers. However, little is known about reasonable surveillance after endoscopic resection of early gastric cancer. We surveyed 190 patients with periodic endoscopic examinations after such a procedure. A total of 18 patients (9.5％) were diagnosed as having residual cancer. The mean interval from mucosectomy to the diagnosis was 208 days. The residual rate was higher statistically in the upper gastric region (p＜0.01). The cumulative one-year residual rate was estimated as 8.8％, the two-year residual rate as 9.7％ and the three-year residual rate as 12.4％. The residual cancer was not until detected after three years. A total of 21 new lesions were detected endoscopically. The mean interval from mucosectomy to diagnosis was 768 days. The macroscopic type was the same in 8 lesions compared with the initial lesion but 13 lesions were different. Fourteen lesions were detected near the initial lesions but 7 lesions were detected far from the initial lesions. The cumulative one-year prevalence rate was estimated as 5.6％. The rate increased to 26.9％ by the time seven years had elapsed.

　Periodical surveillance examination for detecting new lesions is recommended after endoscopic resection of early gastric cancer. The examinations might be repeated at one-year interval and special attention should be paid to the region near the initial lesion.