Blood test for ALL cancers that can spot tumours ten years before any symptoms

A UNIVERSAL cancer test that can diagnose tumours a decade before symptoms appear is being developed by scientists.

Known as a ‘liquid biopsy’, it involves patients providing a blood sample that is run through a laboratory machine for a highly sophisticated analysis.

It scans the blood for any DNA that has been shed by tumours. This starts circulating in the bloodstream long before patients feel symptoms.

The genetic code provided in this ‘circulating tumour DNA’ – known as ctDNA – tells scientists where in the body tumours are growing and how far the cancer has spread.

The test could be available within two years and the eventual goal is to offer it to patients alongside routine checks on their blood pressure and cholesterol at their GP surgery.

Researchers believe that it has the potential to halve the cancer death rate, saving tens of thousands of lives. The first results from trials investigating the accuracy of the tests were unveiled at the world’s largest cancer conference at the weekend.

The tests would be particularly beneficial for those with the deadliest forms of cancer including lung, pancreatic and ovarian, which are usually diagnosed late. One eminent American professor predicted the tests could reduce the cancer death rate by 45 per cent, saving 73,500 lives in the UK each year.

Researchers from the Memorial Sloan Kettering Cancer Centre in New York ran the test on 161 patients already diagnosed with breast, lung or prostate cancer to see if it could accurately detect tumour DNA in their blood.

The results, presented to the American Society for Clinical Oncology conference in Chicago, showed the test could identify the type of tumour in 90 per cent of cases.

Earlier, a team of researchers from Australia and the US presented findings from a separate trial looking at the effectiveness of the test for diagnosing pancreatic cancer, which is notoriously difficult to treat as it is usually only picked up once it has spread to other organs.

The trial, which involved 119 patients already diagnosed with pancreatic cancer, showed the test could accu- rately detect the illness in 55.5 per cent of cases. The next step is to improve accuracy so the test can pick up the vast majority of tumours.

A US firm called Grail, backed by £78million from Microsoft founder Bill Gates and Amazon chief Jeff Bezos, is aiming to get a test on the market in 2019.

The company is also investigating if the same diagnosing technology can eventually be used in a wristband. British experts say it will take longer than two years for the test to be used by GPs in the NHS, but that it will nonetheless transform cancer care.

Dr Nick Turner, from the Institute of Cancer Research and the Royal Marsden Hospital in London, said: ‘ The potential is very exciting.’ Dr Peter Gibbs, an associate professor from the Walter and Eliza Hall Institute of Medical Research in Melbourne, who was involved in the research on the pancreatic test, said: ‘The potential impact of prevention – early diagnosis, screening – is huge.

‘You’d have your cholesterol check, your blood sugar check and DNA tumour check at the same time.’

Experts say the test would initially be offered to patients most at risk of cancer, including the elderly, smokers or those with a family history. After that, it would be rolled out to others.

If the test identified tumours, patients would undergo further scans to confirm their presence. The hope is that at this stage, any tumours would still be relatively small so they could be removed straightforwardly through surgery.

Currently liquid biopsy tests cost about £1,500 a time but they are expected to come down to £155 as they become more widely available.

Professor Bert Vogelstein, from the Johns Hopkins University in Maryland, Baltimore, one of the founders of the liquid biopsy tests, said that if rolled out, the tests would prevent 45 per cent of cancer deaths.

He added: ‘The long-term goal – and perhaps the most important – is early detection before patients are symptomatic. Then you can try and cure it.’

‘The potential impact is huge’