陥凹性早期胃癌の深達度診断における多変量解析の試み

Diagnosis for the Depth of Infiltration in Early Gastric Cancer of Depressed Type, with Reference to an Application of Multivariate Analysis

　早期胃癌の内視鏡診断に際して癌か否かの診断は，直視下生検による組織診あるいは細胞診など顕微鏡レベルの所見によって直接的に確定診断可能であるが，癌深達度を直接診断する方法はない．X線にしろ内視鏡にしろ癌深達度の診断は病巣部の肉眼レベルの所見にもとついて経験的あるいは統計的に診断せざるを得ない宿命を負っている．

　8年前，われわれは切除胃の肉眼所見で判定すれば早期胃癌に類似した進行胃癌が予想以上に多いことを認め（Table 1），それらを“早期類似進行癌”（以下類進癌と略す）と呼び，早期胃癌との鑑別診断の重要陸を指摘した．そして両者の鑑別診断に役立つ指標を詳細に検討し報告した¹⁾²⁾．

　The present authors have reported 8 years ago that cases of advanced gastric cancer grossly mimicking early cancer are more common than expected. These were named as “early simulating advanced cancer”. They pointed out the significance of the depth of infiltration in these. Furthermore, the detail of useful diagnostic criteria for the estimation of the depth in each type of early gastric cancer (by our own classification) was also reported.

　In the present paper, the materials consisted of 269 cases of early gastric cancer of depressed type (Ⅱc with converging folds. Ⅱc＋Ⅲ and Ⅲ＋Ⅱc) and 139 cases of early simulating advanced cancer, both of which were hardly diagnosed. These were investigated with multivariate analysis and computed measurement how correct the estimation as to the depth of cancer infiltration was by combinations of our selected diagnostic criteria.

　The results are as follows:

　1. In cases of type IIc with converging folds and Ⅱc＋Ⅲ type, differentiation between early cancer and the advanced was correct in 71 per cent respectively, However, differentiation between mucosal cancer and submucosal cancer was difficult.

　Usefull diagnostic criteria for differentiation were “characteristic findings of converging folds”, “rigidity of Ⅱc lesion”, “size of Ⅲ lesion” and “size of Ⅱc lesion” and less significant in this order.

　2. In cases of Ⅲ＋Ⅱc type, diffentiation between the early cancer and the advanced was rather difficult, although these were in small number.

　3. However, differentiation between mucosal cancer and advanced cancer was possible over 80 per cent in any type of cancer.

　4. In comparison between result of computed measurement diagnosis and results of hitherto diagnosis by doctors, the former was not all inferior to the latter. Therefore, the computed diagnosis can be expected as useful for diagnosis as to the depth of cancer infiltration. The diagnosis will be much improved in its correctness by detection of futher useful diagnostic criteria.