London, Thanasis Gavos

Particularly encouraging are the results of a large-scale trial in the British NHS health system of a blood test that can detect at least 50 types of cancer in time.

According to the lead researchers from the University of Oxford, the Galleri test shows “great promise”.

Specifically, the test correctly detected two out of three cancers among 5,461 patients who visited their neighborhood primary care doctor with suspicious symptoms in England and Wales.

In 85% of these successful diagnoses, the test was also able to locate the site of the primary cancer.

The way the Galleri test works is by detecting distinct changes in parts of the genetic code that leak into the blood from each different type of cancer. With this “wet biopsy” an early, life-saving diagnosis can be made.

The researchers point out that this is still a work in progress, but they are optimistic that using the test could increase early diagnoses.

75% of those who tested positive for traces of cancer with the test were actually confirmed by further tests to have cancer. Only 2.5% of those who tested negative were later found to have cancer.

These percentages, although satisfactory for the current phase of testing, are not considered accurate enough for scientists to rely solely on this particular blood test with complete certainty. But an 85% accuracy rate achieved is sufficient for a doctor to attribute symptoms that are not easily explained to possible cancer.

“With this kind of prediction from the test we can decide whether to order an endoscopy or a scan and make sure we’re writing the right test from the start,” said lead researcher Professor Mark Middleton.

The Galleri test has been developed by the pharmaceutical company Grail of California. It is also being used by the NHS in Britain on people without symptoms, in a bid to see if it can detect cancer in those cases too.

Initial results from this trial are expected later this year. If successful, NHS England plans to expand the use of the test to a further 1 million people in 2024 and 2025.

As it has been announced in previous stages of testing in Britain, the Galleri test has the special ability to detect difficult-to-detect types of cancer such as bowel, lung, pancreas, larynx, head.