Circulating tumor cells and circulating tumor DNA are areas of research for early cancer detection via liquid biopsies.

“so um this whole idea of can we find them earlier through um blood tests what they're calling liquid biopsies and this is an area of a lot of research now where they're trying to develop these blood tests to detect small numbers of circulating tumor cells or small numbers of circulating tumor DNA because these cancer cells will grow divide undergo cell death as well and they'll shed some elements um into the system um but this is very experimental it's not being used in clinical practice right now but there's a ton of research um on these blood tests and liquid biopsy”