The Significance of DNA Ploidy by Flow Cytometric Measurement in Pancreatic Cancer

Abstract

The cellular DNA content of pancreatic cancer using formalin-fixed, paraffin-embedded specimens from 37 patients whose disease had been treated with surgical resection was determined by flow cytometry. Ploidy and cell cycle parameters were analysed and correlated with clinical and pathologic findings. There were 24 (64. 9%) diploid and 13 non-diploid pancreatic cancers. The median survival of the patients with diploid tumor was 14 months and that of the patients with non-diploid tumor was 8 months, but the difference did not have statistical significance (p=O. 078). And other cytometric parameters such as Gl phase fraction (p=O. 84), S phase fraction (0. 076), G2M phase fraction (p=O. 72), and proliferative index (p=O. 81) did not show any significant prognostic value. The patients with stage I (n=15) had 27 months of median survival, the patients with stage II (n=8) 7 months of median survival, the patients with stage III (n> 15) 9 months of median survival. The differences of survival by stage were the most significant among the parameters which were studied (p=O. 0003). The group which had lymph node metastasis (n> 11) showed 7 months of median survival and the group with negative lymph node (n=26) 12 months. The difference was also significant (p=O. 046). The other clinical parameters such as sex, the size of tumor, and the location of tumor did not have any influence on the prognosis of the pancreatic cancer patients in this study. Multivariate analysis by Weibull's model was used for prediction of survival time. Diploid versus non-diploid DNA content changed to less significant factor after adjustment for stage and lymph node. But the stage of the tumor remained a highly significant prognostic factor even after adjustment for ploidy and lymph node status.