A revolutionary blood test has been shown to diagnose the recurrence of cancer up to a year in advance of conventional scans in a major lung cancer trial.
The test, known as a liquid biopsy, could buy crucial time for doctors by indicating that cancer is growing in the body when tumours are not yet detectable on CT scans and long before the patient becomes aware of physical symptoms.
It works by detecting free-floating mutated DNA, released into the bloodstream by dying cancer cells. In the trial of 100 lung cancer patients, scientists saw precipitous rises in tumour DNA in the blood of patients who would go on to relapse months, or even a year, later.
The findings add to building anticipation that the technology, which is already in widespread use in non-invasive prenatal tests for Down’s syndrome, will have a major impact in cancer medicine.
Nitzan Rosenfeld of the Cancer Research UK Cambridge Institute, who was not involved in the latest trial, predicts that “most if not all” cancer patients will be given the DNA-based tests in future.
