[Cytophotometrically determined DNA content, mitotic index and proliferative activity clinical gastric cancer]

1) Analyses of cytophotometrically determined DNA content and mitotic index (MI) using histologic sections were carried out in 37 advanced gastric carcinomas. According to the linear regression analysis, there were statistically significant correlations of MI with DNA variants such as the peak value, the mean value and the frequency of cells with values exceeding 4c or 6c (%-over 4c or 6c). When the mean MI was calculated according to the %-over 4c or 6c, there were better correlations of higher MI with increased hyperaneuploid levels. 2) Measurement of DNA content and MI were examined in each layer of 46 tumors with serosal invasion. The mitotic counting analysis revealed a significantly higher value in the serosa, compared with findings in the mucosa. Similarly, the deeper the layer, the higher the %-over 6c. This tendency was evident in cases of an undifferentiated type adenocarcinoma. 3) The relationship between DNA ploidy and tumor invasion was studied in 254 tumors. The frequency of aneuploidy increased with invasion into the deeper layers. Especially in cases of the undifferentiated type, aneuploid carcinoma was free at the stage confined to the mucosa, while the rate was 47% for serosal carcinoma. Thus, abnormal DNA fractions appear to be indicative of tumors with a high mitotic activity and a propensity for growing downward rapidly in the gastric wall.