Australian scientists will conduct chest scans on about 2,000 people with high risk of lung cancer to determine if such screenings can help detect the deadly disease in its early stage.

The clinical trial will provide crucial evidence about the effectiveness of a screening programme for the country's most lethal cancer, which claims more than 8,000 lives a year.

People at a high risk of developing lung cancer, predominantly heavy smokers over 55, will undergo regular computer tomography (CT) scans in the trial to see if it can detect the disease before it becomes deadly.

"The cure rate is very low because 75 per cent of lung cancers have already spread by the time they are detected," said Lou Irving, associate professor at Royal Melbourne Hospital in Australia.

"This is partly because the lungs don't have any pain fibres within them, so the cancer can grow quite large in your lungs and spread before you even know that you have it," Irving was quoted as saying by 'Herald Sun'.

"If you can pick it up when it is the size of a peanut there is then the chance to use surgery, which, in very early disease, has a cure rate of 85 per cent," he added.