Flow cytometric DNA content analysis in 708 patients affected by ovarian cancer. Clinical correlations

The flow cytometric DNA Index has been evaluated in 822 samples like primary tumor, metastases and ascitic fluids, obtained from 708 patients affected by ovarian cancer at different clinical FIGO stage: 175 FIGO I, 38 FIGO II, 500 FIGO III and 78 FIGO IV. 292 tumors had a DNA diploid content while the other 530 had a DNA aneuploid content. In 95 patients the DNA index was measured on several samples and, over time, in the same patient showing that the DNA index was very stable. Tumor FIGO stage and ploidy was significantly associated: in patients with tumor FIGO stage I and II, 115 had tumors with diploid DNA content and 98 with aneuploid DNA content, while stages III and IV were more likely to be DNA aneuploid, being 153 with diploid DNA content and 425 with aneuploid DNA content (p < 0.01). The DNA index was also related to the degree of differentiation of the tumors: poorly differentiated tumors were more likely to be DNA aneuploid tumors (p < 0.01). A strong association was found between ploidy and residual tumor size at first surgery : patients with residual tumor size >2 cm had a significantly large number of DNA aneuploid than DNA diploid tumors (p < 0.01). The percentage of the cells in the S phase of the cell cycle evaluated in tumors at FIGO stage III and IV was significantly higher in DNA aneuploid and in poorly differentiated tumors than DNA diploid and well differentiated tumors. Multivariate analysis using Cox model performed in borderline tumors, or in tumors at FIGO I and II, or in tumors at FIGO III and IV clinical stage showed that the DNA index was not considered as an independent prognostic factor in this study. In patients with FIGO III and IV tumors the residual tumor size and histological mucinous and clear cells tumor type were found to be an independent prognostic factors