"The minimally invasive liquid biopsy makes it possible to identify driver mutations and other markers in the blood very precisely. The information is relevant for early clinical decision making throughout the course of the disease. Despite treatment, minimal residual disease (MRD) is typically present. Although its location is not accessible with imaging, it can be characterized by liquid biopsy. In the light of NSCLC heterogenicity, related information has a significant impact on outcome as it enables faster and earlier clinical decision making" explains Prof. Dr. Dr. Klaus Nagels, principal investigator of the study and Chairholder of Healthcare Management and Health Services Research at the University of Bayreuth. Tissue biopsy is still considered to be the gold standard when it comes to the histological analysis of the tumour and the identification of driver mutations. However, the sampling of tumour tissue by tissue biopsy is not always possible. In later stages, tumour tissue becomes undetectable by imaging, as it has been shrunk by therapy, although undetectable minimal residual disease remains; tumour location may be unfavourable; sampling complications may be to be expected or patients may refuse a tissue biopsy. Liquid biopsy is a minimal invasive alternative that can identify driver mutations and other markers of growing importance with a high degree of reliability. Furthermore, NSCLC tumours evolve in the course of the disease, driver mutations change and the tumour becomes resistant to therapy. These genetic changes can be detected at a very early stage with liquid biopsy, long before the tumour becomes detectable with imaging.
"In our study, we modelled typical course of the disease in patients suffering from non-small cell lung cancer. Scenarios involved patients who were diagnosed with tissue biopsy while liquid biopsy was used as add on. So, we were quite conservative. The results suggest that the more comprehensive information on cancer progression obtained with liquid biopsy generates clear patients benefits, as the therapy can be adapted to the state of tumour evolution, thus clinical decision making on therapy selection can be based on precise and early information. For many patients, this results in better clinical treatment outcomes and improved quality of life,” says Nagels.
Another central result of the study concerns the health economic evaluation of liquid biopsy. For the first time, it shows that, in relation to the German health care system, this form of precision diagnostics will not drive up costs for the treatment of non-small cell lung cancer at all. "Liquid biopsy enables longer survival and good quality of life, and moreover, proves to be cost-effecive because it helps to focus therapy on targeted and therefore effective measures already in the early stages of the disease. In this respect, liquid biopsy is already complemented and strengthened by methods of genetic and molecular biological diagnostics - especially NGS (next generation sequencing). It is expected that these diagnostic capabilities will be expanded in the future," says Fabienne Englmeier, first author of the study and doctoral student of Prof. Dr. Dr. Klaus Nagels at the University of Bayreuth.
