外科病理よりみたpm胃癌

Pm Gastric Cancer from the Viewpoint of Surgery and Pathology

　人胃癌の発生は特殊なものを除けば胃粘膜内で行なわれることには議論の余地はない．そして粘膜内にあっても，潰瘍やびらんに直接して発生したものを除けば，粘膜の表面に近い浅い層で行なわれること（Konjetzny²⁾，Büchner⁶⁾，村上⁵⁾）もほぼ確かである．

　このようにして発生した胃癌が，さらにどのような経過を辿って，私どもの目に映るような胃癌の大きさにまで進行するものかは，これまであまり深く考察されていない．ただ慢然と，一点ないしは比較的狭い範囲のある面を中心として，波紋や音波がひろがるように同心円的に拡大するものだという風に考えられがちである．

　We have studied pm gastric cancer by dividing it into pm early cancer and pm Borrmann type cancer. This classification is of great significance especially from the viewpoint of lymph node metastasis and end results. Except for terminal stage of cancer, we generally perform R₂ complete extirpation of the regional lymph nodes. End results of cancer showing early cancer type, including pm cancer hard to distinguish macroscopically from early cancer, are favorable nearing those of sm cancer. However, the five-year-survival rate of pm cancer as a whole is 66.7 percent. That of early cancer type is 93.3 per cent, while Borrmann type shows a far worse rate of 47.6 per cent.

　The reason for the scarcity of surgically treated cases of pm cancer is considered to lie in the fact that of m and sm early cancers there are some that develop slowly and remain within pm and there are others deploping rapidly from the stage of early cancer into s or ss infiltration. In other words, pm Borrmann type shows most frequently Borrmann type II cancer and type III is infrequent. According as cancer advances from pm stage to terminal one, the incidence of Borrmann type III cancer increases, while type II cancer is seen less often. When these facts are taken into account, we can assume that the excavated type of cancer, whether it be early type or Borrmann type, seems to have a propensity to develop rapidly in vertical direction (depth invasion). On the other hand, elevated cancer of pm Borrmann type seems to develope slowly. We are now studying the developing patterns of pm cancer by roughly dividing it either into early cancer type and Borrmann type, or into the elevated variety or excavated one. As a result, slow-developing cancer, or pm Borrman type with a nature to protrude, seems to have real characteristics of pm cancer.