[Characteristics of early gastric cancer accompanied by lymph node metastasis]

We studied the phenotypic expression, DNA ploidy patterns and other clinico-pathological features of early gastric cancers accompanied by lymph node metastasis. Of 241 cases studied, 18 (7.5%) were lymph node-positive. Histologically, 4 were tub1, 7 tub2, 4 sig and 3 por. Seven of the 18 were differentiated type cancers with accompanying undifferentiated type cancer cells in a part of the cancer tissue. Mucin histochemistry showed that 15 of the 18 cancers were composed exclusively of gastric type cells, while the other 3 were composed of intestinal type cells. The incidence of gastric type cells in node-positive cancers was significantly higher (p < 0.05) than that in node-negative cancers. All node-positive mucosal cancers were composed mainly of gastric type cells. These findings indicate that there are many cancers which are originally gastric in type, and that gastric type cancers readily develop lymph node metastasis. On the other hand, a cytofluorometric study showed that 10 tumors were diploid and 8 were aneuploid. There was no statistically significant association between DNA ploidy patterns and the occurrence of lymph node metastasis.