Cell-proliferative activity and its relationship to the histologic type of early gastric cancer.

To evaluate the biological characteristics of gastric carcinoma and of the normal gastric mucosa from which carcinoma seems to develop, we analyzed the DNA content and proliferative activity of cells in 154 patients with primary mucosal gastric cancer and 40 patients with gastric ulcer by flow cytometric analysis. A total of 154 samples from mucosal gastric carcinomas, 154 samples from normal gastric mucosa adjacent to carcinomas and 40 samples from normal gastric mucosa adjacent to gastric ulcers were subjected to analysis. The incidence of DNA aneuploidy of differentiated carcinoma cells (34.3%) was significantly higher than that of undifferentiated carcinoma cells (14.5%, P=0.014). Among the cancers with diploid DNA, the mean value of the proportion of cells in the S phase of the cell cycle in differentiated carcinomas was 6.64% and it was significantly higher than that in undifferentiated carcinomas (5.53%, P=0.01). The mean values for the S and G2 + M phases for cells in the normal gastric mucosa from sites adjacent to the differentiated carcinomas were 5.29% and 1.81%. These values were higher than those for cells in normal gastric mucosa from sites adjacent to undifferentiated carcinomas (4.89% and 1.40%, respectively) and than those for cells in normal mucosa from sites adjacent to gastric ulcers (4.48% and 1.68%, respectively). During the early phase of gastric cancer, differentiated carcinoma seems to develop from gastric mucosa where cells have high proliferative activity. Reflecting this biological characteristic, the cells of differentiated carcinomas also have high proliferative activity.