Role of circulating free Alu DNA in endometrial cancer

Background: Endometrial cancer (EC) is the most common cancer of the female genital tract. However, no screening method for EC has been established yet. In this study, we evaluated the cell-free DNA in EC. Methods: Fifteen healthy individuals, 9 with benign gynecologic diseases, and 53 with ECs were included in this study. Alu sequences in free DNA fragments were used as surrogate markers, and cell-free DNA density was measured by quantitative real-time polymerase chain reaction. Results: The cell-free DNA levels in ECs tended to be higher than in benign condition (healthy individuals + benign gynecologic diseases, n = 24; P = 0.095). There was no significant difference in cell-free DNA among stage or histological grade of EC, and no significant change in cell-free DNA before and after operation (P = 0.25): Moreover, in 19 ECs, cell-free DNA decreased after operation, however, in 6 ECs, cell-free DNA did not decrease. Three ECs recurred, and cell-free DNA did not decrease in these cases. Conclusions: Measurement of cell-free DNA is not useful for EC screening; however, the change of cell-free DNA in a patient may be a prognostic biomarker of EC.