内視鏡の立場からみた早期胃癌診断の限界

Possible Limitation of Endoscopy for the Diagnosis of Early Gastric Cancer

　いま，筆者の手もとに2つの大学の早期胃癌診断の資料がある．1つは東京女子医科大学消化器病センターのもので，鈴木が中心になってまとめてくれたものである．昨目着いたばかりである．もう1つは山口大学第1内科のデータで，永富が中心になって整理したものである．いよいよ書くかなとペンを握った現在では，まだ資料をパラパラとめくってみたに過ぎないし，内容もしっかりつかんでいるわけではない．もちろん，症例の数は，東京女子医科大学のほうが，紹介外来制をとっており，内視鏡診断がある程度形がととのった最近10力年の症例に限定した山口大学より圧倒的に多い．

　これからこれら2つの材料を分析し，早期胃癌の内視鏡診断の限界をさぐってみようというわけである．整理した結果は，思ったより安心できるような成績かもしれないし，あるいは，無茶苦茶な診断成績で，よくまあこんな診断成績でもって，内視鏡を専門にしているなどと，うそぶけるものだなあと，諸先生をあきれさせるような結末になるかもしれない．そして，内視鏡診断の現況のだらしなさに怒りと悲しみを感ずるようなことになるかもしれない．

　The usefulness of endoscopy for the diagnosis of early gastric cancer is discussed on the basis of the results taken from two institutions.

　601 cases with 688 lesions of early gastric cancer in Tokyo Women's Medical College Hospital (institution A), and 117 cases with 122 lesions in The First Division of Internal Medicine, Yamaguchi University Hospital (institution B).

　In institution A, 95.5％ of total lesions with elevated type ranging from 4 cm to 2 cm in diameter, and 73.2％ of the same type, from 2 cm to 0 cm were endoscopically suspected of early gastric cancer, while 80.7％ of lesions with depressed type ranging from 4 cm to 2 cm in diameter, and 78. 5％ of the same lesions, from 2 cm to 0 cm were diagnosed by endoscopy.

　In institution B, 91.8％ of the lesions with early gastric cancer could be diagnosed by endoscopic findings.

　In regards to the invasion of cancer cells, the tumor cells stayed just in the mucosal layer (m) or the submucosal layer (sm) in 91.8％ of total lesions of early gastric cancer which were diagnosed by endoscopy in institution B. On the other hand, tumor cells invaded the proper muscle coat (pm) in the lesions of advanced gastric cancer, in which early gastric cancer was highly suspected by endoscopy.

　Although the incidence of early gastric cancer found at the E-G junction was relatively higher in institution A, this result may be due to increased number of experiences of forviewing gastrofiberscope.

　Minute gastric cancer, less than 10 mm in diameter, was found out in 70 cases including 81 lesions in institution A. Forty two out of 81 (51％) lesions were highly suspected to be minute gastric cancer before operation. As the evaluation of diagnostic methods for minute cancer, fluoroscopic examination was available for 20 (53％) out of 38 lesions, while endoscopy diagnosed clearly of this cancer in 33 (87％) out of 38 lesions. Histological diagnostic accuracy using biopsy specimen was 92％.

　Results mentioned above indicate the possible limitation of endoscopy for the diagnosis of early gastric cancer.