Flow cytometric analysis of nuclear DNA heterogeneity in gastric cancer

Flow cytometric analysis of nuclear DNA ploidy was performed to evaluate the clinical significance of DNA-ploidy heterogeneity and DNA-index heterogeneity between the superficial layer and the deep layer of the tumor obtained from 88 advanced gastric cancer patients. DNA-ploidy heterogeneity was observed in 28 patients (31.8%) and characterized mainly by diploidy in the superficial layer and aneuploidy in the deep layer. More than 10% difference in the DNA index among aneuploidy (DNA-index heterogeneity) was observed in 10 (26.3%) of 38 patients with aneuploidy. There was no tendency for the DNA index to increase with deep infiltration. DNA-ploidy and DNA-index heterogeneities were not correlated with the various clinicopathological characteristics. Patients with aneuploidy had significantly poorer prognosis than did those with diploidy. The survival rate for patients with DNA heterogeneity was not significantly different from that for patients without DNA heterogeneity. These results suggest that the DNA-ploidy pattern may be an important prognostic factor, but that DNA heterogeneity may not have an impact on the survival in advanced gastric cancer.