早期胃癌の内視鏡的切除―治癒判定基準と予後との関係からみた問題点

Endoscopical Resection for Early Gastric Cancer Measuring 1 cm or Less in Size

要旨　外科的切除された1cm以下の早期癌87例の癌浸潤先進部を検討し，陥凹型では4.1％，隆起型では7.1％に数個の正常腺管を挾んで非連続的に癌が認められ，最大幅は5腺管であったことから，内視鏡的切除の標本において癌と断端との間に正常腺管が10腺管介在することを根治切除判定の基準と定め，切除断端所見と予後の関係を調べた．当科で1cm以下の内視鏡的切除を行った58例61病変を対象にした．切除標本は平板に固定し，2mm間隔で全割し，深達度と粘膜面上での拡がりについて調べ，術後6か月以上（平均観察期間は21.4か月）経過観察し予後を判定した．癌と切除断端との間に正常腺管が10腺管（距離にして約2mm）以上ある34病変では再発はなく完全切除と考えられ，断端に癌は認めないが10腺管以下の17病変では17.6％に再発がみられ，不完全切除と考えられた．明らかに断端に癌陽性の遺残切除10病変では40％に再発がみられた．したがって，再発は切除断端の所見に左右され，根治を目的とした場合は完全切除の判定が必要と考えられ，また，不完全切除例と遺残切除例は胃角部から胃体部の小彎と後壁に多くみられ，占居部位による技術的な問題があると考えられた．

　Endoscopic therapy of gastric cancer has been mainly performed in non resectable cases of early cancer, for example in patients having severe complications, in the high-aged group and in patients refusing an operation. Recently, endoscopic polypectomy has made it possible to doradical resection for small polypoid cancers in resectable cases. Furthermore, we resected small depressed cancers which were diagnosed as cancers limited to the mucosa. The indication to perform the endoscopical resection instead of surgery was determined foreach cancer macroscopically (x-ray and endoscopy) as follows; 1. Measuring less than l cm in size (elevated and depressed type) 2. Not accompanied with converging folds, and having shallow depression without mound-like elevation (depressed-type).

　According to those indications, 23 elevated, and 38 depressed-type early gastric cancers were resected by endoscopic polypectomy usingh ighfrequency electric current, and the resected specimens were surveyed pathologically. Except for l case, 57 differentiated-type cancers were limited to the mucosa, but one of four cases of undifferentiated-type cancers had invaded the submucosa. Relationship between the prognosis (the average follow-up interval was 21 months) and the histological distance from the edge of the specimen to the margin of the cancer was discussed. None of 34 cases having a distance of more than 2 mm was recurrent. On the other hand, 3 of 17 cases having a distance of less than 2 mm were recurrent at the site of resection, and 4 of 10 cases where the cancer obviously had spread to the edge of the specimen were found to have recurred. Most of all the carcinomas resected completely, but those in the gastric body were resected incompletely.