Background: Although it is important to determine any relationship between tumor DNA ploidy and its biologic behavior, the correlation between DNA ploidy and the prognosis of patients with ovarian cancer is not conclusive. Accordingly, the authors evaluated the clinical application of DNA ploidy in ovarian cancer.
Methods: Flow cytometric measurements were performed in 45 selected patients with well-differentiated serous cystadenocarcinoma of the ovary, Stages Ic-IV. All of them had the same surgical procedure, with retroperitoneal lymphadenectomy including paraaortic nodes, followed by the same postoperative chemotherapeutic regimen.
Results: Of the 45 ovarian cancers, 28 were diploid and 17 were aneuploid. The 2-year survival rate and the estimated 5-year survival rate for patients with diploid tumors were significantly greater than those for patients with aneuploid tumors (73.2% versus 46.7% and 29.1% versus 22.4%, respectively). The 2-year survival rate in patients with advanced disease (Stage III or IV) was also significantly higher for those with diploid tumors (53.3% versus 37.4%, respectively), but the estimated 5-year survival rate was similar in both groups (8.9% versus 9.1%, respectively). Patients with advanced disease had aneuploid tumors more frequently than those with early-stage disease. A significantly higher incidence of retroperitoneal lymph node metastasis was observed in aneuploid tumors than in diploid tumors (43.8% in diploid tumors versus 86.7% in aneuploid tumors). The authors found no difference in the response to chemotherapy between diploid and aneuploid tumors.
Conclusions: Although tumor DNA ploidy was not as reliable as conventional parameters such as surgical stage in establishing prognosis, it may provide an indicator of lymph node involvement.