„Liquid biopsy“ – Einsatzmöglichkeiten in der molekularen Tumordiagnostik

Background: The analysis of bodily fluids (“liquid biopsy”) constitutes a minimally invasive and easily repeatable method for retrieving diagnostically evaluable sample material. Methods: This article is based on selective literature research in the PubMed database on the topic of liquid biopsy. Results: Liquid biopsies comprise predominantly blood, but also all other bodily fluids (urine, saliva, etc.). For subsequent examinations, relevant particles—including circulating tumor cells, cell-free nucleic acids, and exosomes—are isolated from the fluid. Various molecular diagnostic procedures can then be used to address different clinical questions. Potential clinical applications include screening and early diagnosis of malignant diseases, therapeutically relevant molecular tumor profiling, estimation of the response to a specific drug, therapeutic monitoring, and early detection of disease relapse. Potential drawbacks in the application of liquid biopsies relate to the relatively low numbers of circulating tumor cells or low amounts of cell-free nucleic acids in blood, to the sometimes complex isolation and analysis techniques, and to factors inherent to tumor biology, which can have an influence on the results and the value of the tests.