Potential of Cell-free Circulating DNA in Diagnosis of Cancer

Abstract

Circulating cellfree DNA (cfDNA) is characterized as extracellular DNA that may be present in the blood of healthy individuals in low concentrations. CfDNA is released by apoptosis or necrosis into the bloodstream. Increased levels are found in pathological conditions, such as inflammation, autoimmune diseases, or stress. Significant increase of cfDNA is particularly evident in patients with malignancies, especially in the advanced stages of the disease. In this case, the tumor specific cfDNA is released by necrosis from the cells of primary tumor and metastases. Recently, many studies concentrate on the so called liquid biopsies that allow detection of circulating tumor cells and circulating nucleic acids from peripheral blood for tumor diagnostics. Quantitative methods and detection of genetic and epigenetic alternations of cfDNA in patients with different malignancies have potential applications in molecular diagnosis, prognosis, monitoring of disease progression and response to treatment. This review focuses on potential utility of cfDNA as a blood biomarker in selected solid tumors and hematologic malignancies.Key words: circulating cellfree DNA - tumor marker - solid tumors - hematological malignanciesThis study was supported by grant of Internal Grant Agency of the Czech Ministry of Health NT14575.The authors declare they have no potential conflicts of interest concerning drugs, products, orservices used in the study.The Editorial Board declares that the manuscript met the ICMJE "uniform requirements" for biomedical papers.Submitted: 13. 3. 2015Accepted: 18. 5. 2015.