Test that spots cancer before symptoms start

A REVOLUTIONARY blood test for cancer that can detect the disease years before full-blown symptoms develop has been unveiled by British scientists.

Likened to a smoke detector, the £35 cancer test could save lives by providing early warnings.

People with cancer develop mutations on the surface of their red blood cells, the researchers from Swansea University said.

The changes are quite small. Someone with cancer has around 50 mutated red blood cells per million, compared to a figure of only about six mutations for a healthy person. But this is enough to pick out the disease in 80 per cent of cases.

The test, which has been pioneered on gullet cancer, simply involves a patient giving a sample of blood for analysis.

Gullet, or oesophageal cancer, is hard to detect because it is only when the tumour becomes large that it shows symptoms – difficulty in swallowing.

Currently, only 15 per cent of people diagnosed with oesophageal cancer survive more than five years.

The disease is often only discovered late on following a painful endoscopy in which a tube with a camera is put down a patient’s throat.

Each year in the UK, 7,000 people die from gullet cancer, which is commonly caused by acid reflux or heartburn, when acidic stomach contents go up into the gullet, where they cause cells to become malignant.

While the research is still in its infancy, researchers say that in theory the test could also work with other cancers and they now plan to test it on pancreatic cancer. Professor Gareth Jenkins presented the research

‘Like a smoke detector’

at the British Science Festival in Swansea.

Tests have been carried out on 300 people – healthy volunteers, patients with a pre- cancerous condition and those with fullblown cancer.

Professor Jenkins said: ‘ The test can be likened to a “cancer smoke detector” because a smoke detector does not detect the presence of fire in our homes but its by-product – smoke.

‘The test detects cancer by detecting the “smoke” – the mutated blood cells. The old adage of no smoke without fire also applies to “no cancer without mutation” as mutation is the main driving force for cancer development.

‘This is a novel way for testing for the presence of cancer. There is a desperate need for better, earlier diagnostic approaches.’

Professor Jenkins said the test takes only a few hours and is carried out on a device known as a flow cytometer, which is common in hospitals and uses lasers to analyse individual cells.

He also said his team chose to do a blood test for oesophageal cancer because of its ‘woeful survival rates’. ‘The problem is that it doesn’t present itself at an early stage,’ said Professor Jenkins. ‘And most cases are diagnosed when they are far more advanced.’

Cancer Research said finding new ways to detect cancer early – especially those that are hardto-treat such as oesophageal cancer – was vital to improve a patient’s chances of survival.

Dr Aine McCarthy, the charity’s senior science information officer, said: ‘Studies like this, which used blood samples to detect background DNA damage as a sign of cancer, are exciting because they could lead to more oesophageal cancers being diagnosed in the early stages.’

But she added that larger scale studies were now needed ‘ to confirm the results and show the test is reliable’ before it can be used in clinics.