Plasma nucleic acids in the diagnosis and management of malignant disease.

BACKGROUND: There is a need for development of molecular markers of cancer that can be used clinically for the detection, prognostication, and monitoring of cancer. Recently, there has been much interest in the potential use of nucleic acid markers in plasma and serum for this purpose. APPROACH: We reviewed published literature up to 2002 on the topic, with a particular emphasis on reports published between 1996 and 2002. CONTENT: The nucleic acid markers described in plasma and serum include oncogene mutations/amplifications, microsatellite alterations, and gene rearrangements. Such markers have been described in many cancer types, including lung, colon, and breast. Epigenetic alterations, such as aberrant promoter methylation, have been identified in plasma and serum. Viral nucleic acid markers, such as Epstein-Barr virus DNA in plasma and serum, are reviewed in detail with regard to their application to virus-associated cancers such as nasopharyngeal carcinoma and various lymphomas. More recently, mitochondrial DNA and tumor-related mRNAs have been identified in plasma and serum from patients with several types of tumors.
CONCLUSIONS: Circulating nucleic acids are an emerging class of molecular tumor markers. Their wide applicability and clinical relationship with the malignant state will likely grant them increasing clinical importance in the near future.