I actually know a little about this through my work. Cell-free DNA (CfDNA) Has been known about for a few decades, but has become more of a focus in recent years because of the advent of immunotherapies, which are often highly targeted drugs. CfDNA has also been used in "liquid biopsies" i.e, a simple blood draw, because it can help you profile the tumor and location of the cancer.

In my field, we all think that CfDNA testing will eventually become a standard thing that will go along with your annual physical's blood test, because it has predictive/preventative abilities.