If you’re around my age (not telling), you’ve probably had your blood drawn, maybe even regularly. Electrolytes, sugars, cholesterol, liver and kidney stuff, HIV testing and the like. But imagine that that same blood sample could tell you whether or not you have any one of 40 cancers? The future is upon us.
Written in Blood
Welcome to the age of “liquid biopsies.” These are “tests done on a sample of blood to look for cancer cells…or for pieces of DNA from tumor cells.” It’s subtle biology, but when normal cells die, their contents spill into the bloodstream, loaded with all sorts of genetic material. There are cells in the blood whose job it is to clear up this debris quickly. When cancer cells die, because there are so many of them, the amount of debris is larger and it takes longer to mop up. This lets us detect small amounts cancer tumor DNA (ctDNA) and other genomic fragments with next gen technology. Add to this a little genomic crunching, and this new breed of blood tests can now find cancers, tell you if treatments are working, and help us to better understand how cancers change.
Liquid biopsies essentially paint portraits of cancers far better than that currently used, and more invasive, tissue biopsies. In fact, it’s the same technology developed two decades ago that enabled us to check a baby’s sex early on in pregnancy, and now allows us to screen for fetal disorders just by drawing mom’s blood. It really is Star Trekkian technology.
Portraits of Fertility
There is something in the field of male infertility that I think looks a lot like a liquid biopsy: Sperm Mapping. The resemblance begins with the fact that it is only slightly more invasive than a blood draw. And, the testicular sample is also (essentially a) liquid that is smeared on a slide, just like blood. And, it tells you a lot about what’s going on inside. In fact, it finds things like sperm better than anything else out there right now. No, it’s not a genomic test (yet), and it won’t tell your cancer fortune well before it happens. But it is a workhorse of a tool that will tell if you can be a father or not. And to many, that matters as much as having cancer. Now that’s a liquid biopsy with some real punch to it.