Ten thousand smokers are to take part in trials of a blood test for lung cancer that can detect the disease up to five years earlier than it would normally be found.

The test has been shown to work in the US after being introduced two years ago and the trial is designed to establish whether it is cost-effective for the UK. Sir Harry Burns, Scotland's Chief Medical Officer, said that by catching the disease early patients were much fitter when treatment started and would have a much better chance of survival. Treatment could also be less aggressive.

"The earlier a cancer is diagnosed, the greater the chance it can be treated successfully, and 85 per cent of patients with lung cancer remain undiagnosed until the disease has reached an advanced stage," he said. The trials will take place in Scotland and will start this year, with the first results expected in 2014. It is part of the Detect Cancer Early programme in Scotland that is designed to increase early detection rates by 25 per cent.

Professor John Robertson, of Oncimmune Ltd which developed the procedure, said: "The test is highly reproducible and will I believe lead to significant improvement in prognosis for a substantial number of lung cancer sufferers."