A revolutionary blood test, which acts like a smoke detector to spot cancer up to 10 years before symptoms appear, could be available within five years.
Scientists at Swansea University have discovered that mutations occur in red blood cells way before any signs of cancer are evident.
They have devised a simple test which hunts for the mutations and can indicate if cancer is present in just a couple of hours.
Although the test has so far only been carried out on patients with cancer of the oesophagus, the scientists say it should work for other types of the disease, and are beginning new trials on pancreatic cancer.
The university says the test, which costs just £35 (NZ$63), picks up cancer "earlier than ever before" offering hope to patients that their illness could be spotted when it could be easily treated with surgery, which is likely to save lives.
Professor Gareth Jenkins, who led the study, 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 it's by-product - smoke.
"This 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 driving force for cancer development."
The finger-prick test could be used as a general screening tool for people visiting their GP or to check whether symptoms such as reflux are actually caused by cancer.
The scientists look for mutated blood cells that have lost sticky Velcro-like proteins, which help other proteins attach to the cell. In healthy people only a few mutated cells are found per million. But in people with cancer the figure jumps by more than ten fold.
Scientists think it may even pick up pre-cancernous patients who are at high risk of developing disease but who do not yet have cancer and may not develop it for another 10 years.
Dr Hasan Haboubi, who is developing the test as part of his PhD project said: "We found (precancerous) patients do push up a little bit higher towards the cancer levels (on the test)
"We know that those patients almost inevitably develop cancer within 10 years."
The team is now carrying out a validation study to check that the test does not throw up too many false positives, or miss cancer.
Professor Jenkins said the team chose oesophageal cancer for the trial because of its "woeful survival rates", often because of late diagnosis. The median survival time is just 12 months while just 15 per cent of people live for five years.
"The problem is that it doesn't present itself at an early stage, and most cases are diagnosed when they are far more advanced," he told the British Science Festival in Swansea.
The charity Cancer Research UK said finding new ways to detect cancer early was vital to improving the chance of survival.
Dr Aine McCarthy, the charity's senior information officer, said: "Studies like this, which use blood samples to detect background DNA damage as a sign of cancer are exciting because they could lead to more oesophogeal cancers being diagnosed in the early stages.
"But larger scale studies are needed to confirm the results and show the test is reliable before it can be used in the clinic."
Cancer: Five red flags to never ignore
• Any sudden weight loss when not dieting
• Blood in your faeces or urine
• Coughing up blood
• A lump in the breast, groin, testes, side of the neck or armpit
• Severe, unexplained pains or aches