This blood test can diagnose unreachable brain tumors
A liquid biopsy for diagnosing inaccessible brain tumors was granted U.S. FDA Breakthrough Device designation.
A prospective, blinded study out of Imperial College London demonstrated that the test was “highly accurate” in diagnosing inaccessible brain tumors using 15 ml of blood.
The company developing the test, Datar Cancer Genetics, previously had its early-stage breast and prostate cancer detection tests also obtain Breakthrough Device status—the first liquid biopsies to receive this designation.
Why are liquid biopsies a big deal for brain cancer?
Brain tumors are a leading killer. They’re the 12th most lethal cancer—250,000 adults die from the disease annually.
Currently, diagnosing brain tumors is a complex and invasive process, requiring surgical biopsy and tissue resection for histopathological evaluation.
Plus, these surgical biopsies are impossible to perform in almost 40% of advanced brain tumor cases. This leaves a lot of patients without crucial, life-saving medical diagnoses—patients whose prognoses could change with an available alternative.
This is where Datar’s TriNetra™-Glio liquid biopsy comes in. The test detects extremely rare—and therefore challenging to detect—cells released from brain tumors into the bloodstream. This cell detection also distinguishes the test from previous liquid biopsies, which relied on identifying molecular indicators of disease rather than cells.
Dr. Kevin O’Neill, the lead researcher behind the study, said that this distinction gives the test “true diagnostic utility.”
“As a surgeon working on other technologies to define the tumor and functional boundary during surgery to a molecular level of accuracy and to shorten the diagnostic pathway that would inform surgeons, I find this technology of significant interest,” he said. “In particular, the intended indication to provide a liquid biopsy diagnosis from a simple blood test where tumors are deemed inoperable or inaccessible will truly address an unmet clinical need.”
Liquid biopsies move out from under Theranos’ shadow
The unmet clinical need Dr. O’Neill mentioned is making this development a public health priority.
In the U.S., President Biden’s Cancer Moonshot has prompted the National Cancer Institute (NCI) to undertake a four-year pilot study of over 24,000 participants to evaluate the efficacy of more liquid biopsies.
And the MedTech industry is taking up the torch.
As indicated by Datar’s growing portfolio of blood tests for different cancers, liquid biopsy adoption is increasing across the board. The technology is clearly moving out from under the shadow of infamous blood test company Theranos’ dark legacy.
Global MedTech startups make up a significant portion of developers. Notable liquid biopsy startups include IMB Dx in South Korea, Saga Diagnostics in Sweden, and BioCaptiva in the UK.
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Our cautious optimism about liquid biopsies
The potential benefits of accessible, significantly less invasive cancer screening tools are welcome and exciting. This is especially true in cases like the 40% of advanced brain cancer patients who are ineligible for surgical biopsy.
However, our optimism comes with a note of caution.
Some of these tests have been shown to produce false positives in asymptomatic patients and therefore lead to unnecessary, expensive, and emotionally-taxing follow-up screening.
In a recent issue of MedTech Pulse, we discussed our skepticism about the MedTech industry’s promotion of expensive diagnostic measures to the general public, despite evidence of widespread false positives.
Statistically, when it comes to whole-body MRIs, the rate of false positives outweighs the benefit for patients who receive a correct early cancer diagnosis, leading to unnecessary, expensive, and emotionally-taxing follow-up testing.
Critics who discussed the growing adoption of liquid biopsies with the New York Times also highlighted that, regardless of their diagnostic efficacy, the tests could simply amount to an expensive tool that does not actually reduce cancer deaths. After all, with current treatments, early diagnosis does not necessarily correlate with increased survival for aggressive cancers (such as many brain tumors).
For now, we are cautiously optimistic about this new frontier of cancer screening—especially when it comes to liquid biopsy tests, which have undergone a higher level of regulatory scrutiny, including FDA approval.
As the technology advances, such as with Datar’s new brain tumor test, we hope the utility of available tests make them more of a life-saving tool than an unnecessary health expense.