[Surgical treatment of gastric cancer based on biological behavior]

In this paper, we discuss the biological behavior considered important in surgical treatment for gastric cancer. Of the types of early gastric cancer, the Borrmann type, the histologically well differentiated type and that with metastasis to the lymph nodes belong to the high-risk group. In pm gastric cancer where cancer has infiltrated to the muscularis gropia, nearly 50% metastasis to the lymph node is observed. This is a therapeutic group for which removal of the lymph nodes is most effective. Of pm gastric cancer, the prognosis of the well differentiated type is poor. Adjuvant chemotherapy proves considerably effective for this type. When the relationship between the histologic type and prognosis is examined, the prognosis of the well differentiated type in pm is poor. As the cancer infiltrates to ss, and se, the prognosis of the poorly differentiated type, particularly the scirrhous type, becomes poor. Of the Borrmann IV type with the poorest prognosis among the various types of gastric cancer, there are two kinds, namely, that with a relatively good prognosis and the other with a very poor prognosis. The two can be classified macroscopically. These two groups appear to be different from each other in their biological behavior. Gastric cancer in the aged has a high percentage of metastasis to the lymph nodes, being characterized by a high incidence of Borrmann II type and multiple cancer. The prognosis is not necessarily poor.