January 25, 2018 – Liquid Biopsy Results


Anchor lead: Liquid biopsies for prostate cancer aren’t ready for prime time, Elizabeth Tracey reports

Most biopsies are no fun, but right now for prostate cancer, liquid biopsy, which relies on the presence of cancer DNA in the blood, is no substitute. That’s according to research by Kenneth Pienta, a prostate cancer expert at Johns Hopkins, and colleagues, in a study where blood samples from the same patients were sent to two different commercial labs.

Pienta: Much to our surprise what we discovered was that the two tests didn’t agree very often at all. In fact, about 25% of the time they both showed no mutations, no DNA. But only in about 10% of the time did they actually agree with each other if there was a mutation. We’ve concluded from that that the tests aren’t very good yet. Especially if you’re talking about low volumes of cancer.   :29

Pienta says these tests are certified by a laboratory certification organization, but are not approved by the FDA. He notes that each test costs about $4000, with samples typically being sent to only one lab. At Johns Hopkins, I’m Elizabeth Tracey.