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Turning A Blood Test Into a Biopsy

April 4, 2017, 8:34 PM UTC

Few words in the English language conjure up as much angst as the word “biopsy.” The term evokes not only the fear of a sudden life-changing diagnosis (yes, there’s that), but also the image of a knife: A biopsy, after all, often involves cutting into a person.

But what if it didn’t? What if instead of having to extract tissue from your body to diagnose a disease, a doctor could find out more precise and more comprehensive information—and get it much faster—by taking a small sample of blood? That is the thinking behind the elusive “liquid biopsy”—a concept whose theoretical simplicity has long been sneered at, scoffed at, and had sand kicked in its face by the rude complexity of the challenge.

Sure, physicians already have plenty of blood tests to aid in the diagnosis and prognosis of various cancers, as they do with gobs of other diseases. But for the most part, the proteins measured today (PSA, CA-125, HER2, for examples), often don’t provide enough of the answers—or specific enough answers—needed to make an informed treatment decision.

So, for the past two decades or so, researchers have tried to see if they can get better information from blood-borne snippets of DNA. Could telltale mutations, patterns, or other such “fingerprints” in the blood tell us not only whether or not a person has cancer, but also the exact subtype, where it is, how far it has progressed, the prognosis, and whether or not the disease is likely to respond to certain drugs?

At last, it seems, we may be getting tantalizingly close to those goals. This week, at the humongous (20,000-plus attendee) annual meeting of the American Association for Cancer Research, there were no less than 130 presentations, “poster” sessions, and panels on liquid biopsy studies—with research groups revealing their progress in efforts to detect, amplify, decode, and (most importantly) identify meaningful information from blood-circulating tumor cells (CTCs), other fragments of DNA (cfDNA) and tumor DNA (ctDNA) floating outside the confines of cells, exosomes (tiny sacs that are, somewhat mysteriously, released from cells), and microRNA.

Much of the progress, it’s worth noting, has been made possible by a remarkable collaboration begun in 1991, christened the International Liquid Biopsy Initiative Team, which has helped propel the science forward, thanks to a number of technological breakthroughs. And that team, now led by Luis A. Diaz, at New York’s Memorial Sloan Kettering Cancer Center, got some justifiable praise at the AACR’s opening plenary session on Sunday.

“These people stuck together as a team for over 25 years,” Pat LoRusso, a medical oncologist at the Yale Cancer Center, told me after presenting the AACR’s “Team Science” Award to the group. “[Guided by legendary Johns Hopkins researcher Bert Vogelstein], they first identified that you could find somatic mutations in stool.” (Though, I should point out, it wasn’t until decades later, in 2014, that the FDA approved the first noninvasive DNA-based screening test for colorectal cancer.) Then DNA signatures were revealed in the urine sediment (cells and debris from the urinary tract) of patients with bladder cancer.

“And they kept saying, ‘Let’s go one step beyond that,’” says LoRusso.

Such is the poetry of progress: Let’s go one step beyond that.


This essay appears in today’s edition of the Fortune Brainstorm Health Daily. Get it delivered straight to your inbox.