These life-saving blood tests can spot symptomless cancer
A mammoth investigation into liquid biopsy tests – a new type of blood test – has gleaned fruitful results, with the news that the tests can be used to spot cancer early, with potentially life-saving ramifications.
A Hong Kong study tested around 20,000 men over the course of three years, during which doctors discovered that nasopharyngeal cancer (a form of throat cancer particularly prevalent amongst middle-aged men in south China), could be identified and treated early on, a breakthrough that could save countless lives.
Nasopharyngeal cancer is often associated with infection by the Epstein-Barr virus. Tumour cells could have up to 50 copies of the virus’s genome inside, which, when the cells die, enter the body’s bloodstream. Tumour DNA could then be detected using eminently affordable genetic testing costing in the region of $30 (£23), whereby cancerous material could in a person’s bloodstream before they’ve developed outward symptoms.
The new form of liquid biopsy streamlines the screening process insofar as doctors can hunt for tumour DNA in the bloodstream in larger quantities, instead of seeking out rare bits of cancer cells directly – an arduous and bitty process. This is of particular importance with nasopharyngeal cancer, as it’s an aggressive form of the disease, and sufferers benefit immeasurably from early detection.
Of the 20,000 men screened in the study, 1,112 (5%) of them showed signs of viral DNA. Of this 5%, 309 retained the viral DNA on follow-up tests the following month. A series of tests including endoscope and MRI exams were conducted on the remaining few hundred, out of which 34 were diagnosed with the cancer. Of those who had been treated for nasopharyngeal cancer in the five years preceding the study, only 20% of cases were caught during the cancer’s earliest stage. Of those who had been undergone the study’s liquid biopsies, 71% had their cancer caught during its earliest stage – an impressive 51% markup on early detection.
The study was published on Wednesday by The New England Journal of Medicine, and conducted by the Chinese University of Hong Kong under the leadership of Dr Dennis Lo, a researcher with an impressive track record in the DNA blood testing industry. Dr Lo explained how the work was “very exciting on the larger scale” as it provided a blueprint for tackling a range of other cancers. “We are brick by brick putting that technology into place.”