病理学的所見からみた胃癌の時代的変遷―Helicobacter pylori感染からみて

Chronological Trends of Gastric Carcinoma from the Pathological View Point in Special Reference to Helicobacter pylori Infection

要旨　1979年から2006年までの28年間に外科的切除され当施設に登録された胃癌14,608病変（11,908症例）を対象として，胃癌病理組織像の時代的変遷について検討した．さらに最大径10mm以下の小胃癌480症例524病変を対象に，Helicobacter pylori（H. pylori）陽性率と組織所見について検討を加えた．胃癌頻度は若年者優位に減少し，相対的な低分化型優位癌の減少と分化型優位癌の増加傾向とを認めた．また分化型癌の中でも腸型形質優位癌の相対的な増加傾向を認めた．癌部および周囲粘膜におけるH. pylori陽性率は，分化型優位癌と低分化型優位癌との間に有意差を認めなかった（56.4％ vs 57.5％）．腸型形質優位癌は胃型形質優位癌と比較して，周囲粘膜の腸上皮化生程度が高度でありH. pylori陽性率が低率であった．また腸型形質優位癌の癌組織内部には高率に腸上皮化生成分が混在した．粘液形質により発生母地が異なる一方，H. pylori感染は分化型と低分化型の双方の組織発生に関わっている可能性が示唆された．

　The aim of this study was to clarify the chronological trends of pathological findings of gastric carcinoma. We analysed 14,608 lesions from 11,908 cases of gastric carcinoma, which were surgically resected from 1979 through 2006 in Nigata University Hospital and its related institutes. It was revealed that : 1) There was a decreasing number of gastric carcinoma cases especially among younger patients, 2) There was a relatively increasing number of differentiated-dominant type carcinoma, and 3) There was a relatively increasing number of intestinal-dominant phenotype cases. It was additionally demonstrated through analysis of 524 lesions from 480 cases of small gastric carcinoma : 1) There was no significant difference in H. pylori-positive rate according to histological type, and 2) Carcinoma of gastric-dominant phenotype showed significantly a higher H. pylori-positive rate and a significantly lower intestinal-metaplasia index on surrounding mucosa compared with intestinal-dominant phenotype.