[Liquid biopsy analysis using cell-free DNA (cfDNA): Opportunities and limitations].

Molecular biological analysis of nucleic acids in blood or other bodily fluids (i.e. liquid biopsy analyses) may supplement the pathologists' diagnostic armamentarium in a reasonable way-particularly in cancer precision medicine. Within the field of oncology, liquid biopsy can potentially be used to monitor tumor burden in the blood and to early detect emerging resistance in the course of targeted cancer therapies. An already approved application of liquid biopsy is the detection of epidermal growth factor receptor (EGFR) driver mutations in blood samples of lung cancer patients in those cases where no tissue biopsy is available. However, there is still currently considerable insecurity associated with blood-based DNA analytic methods that must be solved before liquid biopsy can be implemented for broader routine application in the diagnosis of cancer. In this article, the current state of development of liquid biopsy in molecular diagnostics from a pathology point of view is presented.