A liquid biopsy test developed by Thrive Earlier Detection was able to successfully diagnose some cancers, including uterine and thyroid cancer, in women before they showed any symptoms, according to a study published in Science.
According to STAT+, the findings, which were unveiled Tuesday at a virtual annual meeting of the American Association for Cancer Research, mark a first in cancer screening—but some experts caution that the study was exploratory and say more research needs to be conducted.
For the study, researchers in partnership with doctors at Geisinger Health System and Johns Hopkins University, where the test was developed, drew blood from over 10,000 otherwise healthy women between the ages of 65 and 75 and tested them for cancer markers from 10 different organs. If the first test and a confirmatory test both came up positive, and a committee of physicians couldn't discern another explanation for the results, the patient received an imaging test to confirm whether they had cancer and were asked to complete a follow-up survey after one year.
Study shows promise
The researchers found that the test detected 52.1% of cancers, compared with 25% identified by standard cancer screenings. In addition, the researchers found the test was able to identify several cancers that currently have no standard screening method.
The test also had a false-positive rate of less than 0.5% when combined with PET-CT imaging scans, the researchers found. However, the researchers found the false-negative rate was 27.1% across all cancers when used on its own.
Of the more than 10,000 women enrolled in the study, 96 went on to develop cancer. Of those women, 26 had their cancer identified first by Thrive's blood test, 24 had their cancer diagnosed by standard screening methods, and 46 did not receive a diagnosis until after they developed symptoms.
The authors of the study cautioned that the study did come with limitations. A longer follow-up period, for example, likely would reveal more cancers which would increase the rate of false-negative tests. The authors also said the study did not have a diverse population and said that it's unclear whether the liquid biopsy test actually helped any of the participants.
"All that we can confidently conclude at present is that a minimally invasive blood test can be safely used to detect several types of cancer in patients not previously known to have cancer, enabling treatment with intent to cure in at least a subset of individuals," the authors wrote.
Christoph Lengauer, co-founder and CIO of Thrive, called the study a "seminal moment in cancer screening that advances the entire field." He added that the study showed the liquid biopsy test "can be both complementary to existing standard-of-care screening tools, and a significant benefit for many types of cancers like ovarian, appendix and kidney, which do not have any current screening modalities."
However, Anthony Lucci, a professor of surgical oncology at MD Anderson Cancer Center who was not involved in the study, cautioned that the test needs more research.
"The limitations of liquid biopsy are still apparent. Getting to that super low [detection] threshold to find very early-stage disease is still difficult," he said. He added, "The numbers are low, but actually, I think that's the whole problem, currently, with liquid biopsy. We haven't improved the technology to the point where we can find these earliest signs of cancer in many patients."
However, Lucci said he does see a future for the liquid biopsy test in cancer screening. "I have no doubt that in the future, liquid biopsy will be useful as a screening tool where we can identify patients who may be at high risk but may not have signs of cancer," he said (Sheridan, STAT+ [subscription required], 4/28; Hale, FierceBiotech, 4/28; Fidler, BioPharmaDive, 4/28).