Circulating free DNA and p53 antibodies in plasma of patients with ovarian epithelial cancers

Background: This study was conducted in order to evaluate the significance of circulating free DNA (CFDNA), blood plasma p53 antibodies (p53-Ab) and mutations of KRAS gene in the prognosis of ovarian epithelial cancers. Patients and methods: A total of 126 patients were included in this study. KRAS mutations and CFDNA were detected by means of the PCR–restriction fragment length polymorphism (PCR-RFLP) and enriched by the PCR-RFLP method. Enzyme-linked immunosorbent assay was used to analyze plasma p53-Ab. Results: KRAS mutations were detected in 27 (21.4%) of examined tumors. The frequency of KRAS mutations was especially high in mucinous cancers (P < 0.001). CFDNA and p53-Ab were frequently detected in patients with serous cancers in high grade (P < 0.001). The overall survival rate was significantly lower for patients with serous tumors and CFDNA and p53-Ab-positive than negative tumors (P = 0.022 and P < 0.001, respectively). In mucinous ovarian cancer, a worse overall survival was correlated with the KRAS mutations (P = 0.03). Conclusions: The results of the present study suggested that a presence of KRAS mutations in mucinous ovarian cancer and CFDNA and p53-Ab in serous tumors was correlated with the highest risk of cancer progression.