Circulating Cell-Free DNA in Plasma/Serum of Lung Cancer Patients as a Potential Screening and Prognostic Tool

DNA in plasma/serum is a promising noninvasive diag-nostic and prognostic tool requiring only a blood sam-ple, which circumvents the logistic difficulties associ-ated with the use of invasive procedures for serial tumor samplings during screening of lung cancer. Methods: We reviewed English-language reports pub-lished in the MEDLINE database that provided the results of qualitative and quantitative studies on circu-lating DNA in serum/plasma of lung cancer patients. We searched the bibliographies of the retrieved reports and reviews. Abstracts presented at the 2003, 2004, and 2005 annual meetings of the American Society of Clinical Oncology were also reviewed. Results:More than 80 citations were retrieved, of which 33 met our criteria: 22 qualitative studies, and 11 quan