一施設における胃癌の時代的変遷

Chronological Changes in Gastric Cancers Detected at Our Medical Facility

要旨　胃生検が導入された1964年から1991年までに，当院にて内視鏡検査を行い，外科的に切除し，病理学的検索が終了した早期胃癌1,270例；1,407病変，進行胃癌1,661例；1,667病変に，内視鏡的粘膜切除術を施行した早期胃癌76例；79病変を加えて，胃癌の年代的変遷について検討した．臨床的に診断され外科的あるいは内視鏡的に切除される早期胃癌，進行胃癌は年々増加しているが，早期胃癌の占める比率が増加し，最近では全胃癌の六十数％を占めた．早期胃癌の年齢別頻度では，若年者が減少し，高齢者が増加していた．肉眼型別にみると，早期胃癌ではⅡa型，Ⅱc型，Ⅱb型が増加し，Ⅲを伴う病変が減少しており，進行胃癌ではBorrmann4型が増加傾向にあった．大きさをみると，最近10年間で，10mm以下の早期胃癌の臨床診断例が著明に増加していた．多発胃癌の臨床診断例も増加しており，臨床的に診断された多発早期胃癌は8.2％を占めた．占居部位では，早期胃癌の隆起型でC領域が増加し，A領域が減少していた．組織型では，早期胃癌では年次的変動を認めないが，進行癌では，最近10年間は未分化型が分化型を上まわっていた．内視鏡的胃粘膜切除術の完全切除率は50.9％で，満足すべき成績でなく，今後，技術的改善が求められる．

　Since 1964 when gastric biopsy under endoscopic control was first introduced at our hospital, through 1991, endoscopic examinations, surgical resections, and pathological investigations have been completed on 1,407 lesions from 1,270 cases of early gastric cancer, and 1,667 lesions from 1,661 cases of advanced stomach cancer. Added to these data were 79 lesions from 76 cases of early stomach cancer who had undergone endoscopic mucosal resection and chronological follow-up observations to detect recurrences. Annual increases were noted in the incidence of early and advanced stomach cancers that were clinically diagnosed and surgically or endoscopically resected. The percentage increase in early cancer is particularly notable and now comprises more than 60% of total stomach cancers. When the incidence of early cancers is classified according to patient age, the rate has dropped among younger individuals but has increased in the elderly population. When classified according to macroscopic criteria, types Ⅱa, Ⅱc, and Ⅱb showed increases in early stomach cancer, while lesions exhibiting type Ⅲ features were less frequent. Among advanced cancers, the incidence of Borrmann type 4 tended to increase. If classified according to size, there was a marked increase in the incidence of early cancers measuring less than 10 mm. As for the sites occupied by these lesions, the incidence at region C increased while that at region A was lower for the raised type of early stomach cancer. No chronological changes were noted in the incidence of various histological types of early stomach cancer; but among advanced stomach cancers, the incidence of undifferentiated adenocarcinoma has exceeded that of differentiated adenocarcinoma over the past 10 years. The percentage of lesions completely excised by endoscopic mucosal resection was 50.9%, a result which is considered unsatisfactory. At sites such as the middle or upper portion of the gastric corpus, posterior wall, and greater curvature, cancers were often noted to have developed at the gastric stump, indicating a need for innovative application of endoscopic instruments and technological improvements.