Background: The use of cell-free DNA (cfDNA) as a non-invasive biomarker has been evaluated in many types of cancer. This study investigated the prognostic significance of cfDNA level for ovarian cancer.
Materials and methods: Preoperative sera of 36 patients with ovarian cancer and of 16 with benign tumors were analyzed using commercially available copy number assay kits to measure the cfDNA level of genes including beta-2-microglobulin (B2M), member RAS oncogene family (RAB25), claudin 4 (CLDN4) and ATP-binding cassette subfamily F member 2 (ABCF2). Cox regression analysis was used to calculate hazard ratios (HR) and 95% confidence intervals (CI).
Results: cfDNA level of these genes had no association with other prognostic factors of ovarian cancer. In particular, in patients with advanced stage disease, a low RAB25 level was an independent prognostic factor for disease-free survival (HR=18.2, 95% CI=2.0-170.0) and overall survival (HR=33.6, 95% CI=1.8-634.8).
Conclusion: Our findings suggest that the preoperative serum cfDNA level of RAB25 could be a useful biomarker predicting survival outcomes in patients with advanced ovarian cancer.