Abstract
We aimed to summarize the current knowledge about the trends in cfDNA application based on the analysis of clinical trials registered until April 2021. International Clinical Trials Registry Platform (ICTRP) and Clinicaltrials.gov were searched with the keywords: "cf-DNA"; "Circulating DNA"; "Deoxyribonucleic Acid"; and "Cell-Free Deoxyribonucleic Acid". Of 605 clinical trials, we excluded 237 trials, and 368 remaining ones were subject to further analysis. The subject, number of participants, and study design were analyzed. Our scoping review revealed three main trends: oncology (n = 255), non-invasive prenatal diagnostic (n = 48), and organ transplantation (n = 41), and many (n = 22) less common such as sepsis, sport, or autoimmune diseases in 368 clinical trials. Clinical trials are translating theory into clinical care. However, the diagnostic value of cfDNA remains controversial, and diagnostic accuracy still needs to be evaluated. Thus, further studies are necessary until cfDNA turns into a standard in clinical practice.