Blood-based liquid profiling (LP), commonly referred as liquid biopsy, has emerged as a promising, minimal-invasive tool for the diagnostic management of cancer patients. It is based on the detection of circulating tumor DNA (ctDNA) in a background of wildtype DNA by identification of tumor-derived genetic alterations. LP can be used as a personalized tumor marker for detection of minimal residual disease or surveillance of cancer patients, to monitor response to therapy and finally to guide therapeutic decisions. Although the clinical value of LP has been demonstrated in various translational studies, the analysis of ctDNA is not firmly established in standard care so far. This is most likely attributed to the lack of harmonization of preanalytical and analytical procedures as well as the missing inclusion into clinical practical guidelines and the lack of reimbursement.
As the first laboratory in Germany, we have established ctDNA testing in 2016 for the diagnostic management of patients suffering from colorectal cancer as part of clinical care. Retrospetively evaluating this real-world clinical data provides detailled information about the clinical utility of ctDNA analysis, its acceptance by clinicians, the diagnostic performance and reliability, and its integration into clinical workflows in real-world. Moreover, certain limitations hampering successful translation of ctDNA into clinical practice became obvious. Our experience with implementing LP as part of standard care, some pitfalls and future perspectives will be presented and discussed in detail within this presentation.