Fragments of DNA, RNA, and proteins released by dying cancer cells into the bloodstream can be analyzed to detect specific cancer types and stages.

“Out of the breath and in the bloodstream, they leach proteins, they leach DNA, RNA, and even the types of DNA that come out, those little fragments, they have little ends, it's not the whole chromosome that comes out, they get chopped up, the cancer cells die, and out come these little pieces. Those pieces have chemicals on them, the DNA methylation, the clock that can be read, and even at the ends, how they were cut up by enzymes in the cell, can tell you, indeed, that is a stage one liver cancer, even though we picked it up in the bloodstream.”

“cancer cells do this also as it turns out um and the more cancer you have in your body of course the more um well maybe that's not so obvious but is true that the more cancer that is in the body the more um of the copies of cancer DNA that will actually be shed in the bloodstream”