Researchers at Johns Hopkins University have developed a blood test that that can detect signs of eight different types of cancer, according to preliminary trial results published last week (January 18) in Science.
The new diagnostic, dubbed CancerSEEK, is one of many liquid biopsies that have sprung up in recent years. It works by screening patients’ blood for the presence of eight protein biomarkers and mutations in 16 genes.
The team found that the test successfully detected cancer in about 70 percent of 1,005 patients with non-metastasized tumors in the ovary, liver, stomach, pancreas, esophagus, colorectum, lung, or breast. The test’s sensitivity ranged from 33 percent for breast cancer to 98 percent for ovarian cancer. Around 63 percent of the time, the test could even identify where in the body the disease had taken hold. Each test would cost less than $500 to administer, study coauthor Nickolas Papadopoulos, an oncologist at Hopkins, tells the Los Angeles Times.
“They end up with performance that is similar to other approaches, but with what looks to be a much more cost-effective approach,” Nitzan Rosenfeld, a cancer researcher at the University of Cambridge who was not involved in the work, tells Nature.
Seven of the 812 tests in healthy control subjects returned false positive results, however. Because the proteins that the test detects may also be present in the bloodstreams of healthy individuals with inflammatory diseases unrelated to cancer, false positives may be higher in the general population, Catherine Alix-Panabières, a cancer researcher at the University of Montpellier in France who was not involved in the study, tells Nature.
Despite that concern, the researchers say they think CancerSEEK is ready for testing as a screening tool. “A test does not have to be perfect to be useful,” Papadopoulos tells Science. A study to validate CancerSEEK in more than 10,000 healthy individuals has already begun, and researchers will follow up with participants in five years.
While many researchers have expressed enthusiasm about the potential of liquid biopsy in cancer detection, others have warned of the technique’s pitfalls. Last December, another team at Hopkins reported in JAMA Oncology that two different biopsies gave conflicting results for the same patient. The results were “so alarming that we decided . . . to warn other oncologists,” study coauthor Gonzalo Torga, a postdoctoral fellow at Hopkins, told STAT.