[Quantitative estimation of malignancy of gastric cancer by DNA ploidy and proliferative activities]

Paraffin-embedded tumor samples from 493 patients with gastric cancer were analyzed by DNA flow cytometry, and proliferative activities of 155 tumors were measured by bromodeoxyuridine (BrdU) labeling, Ki-67 monoclonal antibody (Mab), and anti-p105 Mab. The results were correlated with clinicopathological findings and patients prognoses. Of the 493 patients, 183 (37%), 225 (46%), and 85 (17%) showed diploid, single DNA a neuploid, and DNA-multiploid. The relative risk of death was three-fold higher in DNA-multiploid tumors than in DNA-diploid tumors. BrdU labeling indices also proved to be an independent prognostic factor. Multiploid tumors had the highest median BrdU LI associated with the most frequent lymph node metastases and hepatic metastases. When the DNA histogram and all the clinicopathological parameters were entered simultaneously into the Cox regression model, DNA ploidy, hepatic metastasis, peritoneal dissemination, BrdU LI, and nodal status emerged as independent prognostic parameters. These results indicate that DNA ploidy and proliferative activities may be useful prognostic factors for the patients with gastric cancer.