Liquid biopsies have shown to be a non-invasive test for the detection of advanced cancer by measuring the levels circulating tumour DNA (ctDNA) in the blood of cancer patients. Much of the published research uses ctDNA for the detection of advanced tumours; however, detection of early-stage tumours has proven more difficult. Liquid biopsies also have the potential for identifying personalised therapies and for assessing treatment response.
Recent research from Johns Hopkins University in Baltimore, USA, assessed a new form of liquid biopsy, which appears to have overcome some of the major challenges of previous tests. Earlier studies focused on tumour DNA found in blood samples to detect a specific form of cancer; the new test assesses levels of circulating proteins along with mutations in cell-free DNA.
The new test, called CancerSEEK, was shown to be able to identify eight different cancers, including ovarian, liver, stomach, lung, oesophagus, colorectal, pancreas and breast. The test was positive in 70% of the eight cancer types, and appears to have overcome a major concern for practitioners and patients by reducing false-positive results to a tiny fraction.