Is the role of circulating DNA as a biomarker of cancer being prematurely overrated?

Background: Circulating DNA is utilized widely as a genetic biomarker in a variety of pathological conditions, mainly in cancerous conditions. Quantification of circulating DNA and identifying the frequencies of a variety of mutations, microsatellite alterations and gene promoter methylation are the main foci of research on circulating DNA. Content: A compilation of research reports available to us were reviewed to highlight the rather great variety of methods presently used to isolate circulating DNA, the lack Of uniformity in presenting and interpreting quantitative research data as well as the virtual absence of information regarding the structure and function of circulating DNA. Conclusions: The information compelled LIS to Conclude that the application of circulating DNA as an unambiguous biomarker is currently overrated. We therefore emphasize the need for elucidating the prevailing questions regarding the origin, function and significance of these nucleic acid molecules before utilizing circulating DNA as a biomarker. (c) 2009 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.