Background: To improve the outcome of endometrial cancer patients, a more accurate prognostic assessment is mandatory. The aims of the study were to evaluate the role of flow cytometric DNA ploidy as an independent prognostic factor in patients with endometrial cancer and to verify if ploidy was able to distinguish patients with different prognosis into homogeneous subgroups for grade of differentiation and stage.
Methods: In a prospective study, DNA ploidy was evaluated from fresh tumor samples in 174 endometrial cancer patients who underwent surgery as the first treatment. Ploidy, as well as classical parameters, were analyzed in relation to the length of disease-free survival and disease-specific survival.
Results: DNA aneuploidy was found in 49 patients (28.2%). Patients with DNA-aneuploid tumors had a significantly reduced disease-free interval and disease-specific survival (P < .0001). The 10-year survival probability was 53.2% for DNA-aneuploid patients and 91.0% for patients with DNA-diploid tumors. By multivariate analysis DNA-aneuploid type was the strongest independent predictor of poor outcome, followed by age and stage. Patients with DNA-aneuploid tumor had a significantly higher risk ratio for recurrence (5.03) and death due to disease (6.50) than patients with DNA-diploid tumors. Stratification by DNA-ploidy within each group by grade of differentiation allowed identification of patients with significantly different outcome. In grade 2 tumors, 10-year survival was 45.0% in aneuploid cases and 91.9% in diploid cases (P < .0001). Patients with advanced-stage (>I) diploid tumor did significantly better than patients with stage I aneuploid tumor (P = .04).
Conclusions: The presence of DNA-aneuploid type in endometrial cancer identifies high-risk cases among the patients considered 'low risk' according to stage and grade of differentiation.