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.