A new blood test, trialled on thousands of Scots, can detect early signs of lung cancer before symptoms have developed.

Research, carried out by University of St Andrews professor Frank Sullivan on 12,200 people considered to be at a high risk, found that those who took the test were more likely to be diagnosed earlier.

Approximately 460 men and 340 women for every 100,000 Scottish citizens are diagnosed with lung cancer every year, meaning the country has one of the highest rates of lung cancer in the world.

Professor Sullivan said the findings, presented at the 2019 World Conference on Lung Cancer, could have "globally significant implications" and experts are hopeful that the test will be rolled out across the globe.

About 85% of patients in the UK are left undiagnosed until the disease has spread to other parts of the body and currently less than 9% of all lung cancer patients reach their five-year survival mark.

The EarlyCDT®-Lung Test is a novel autoantibody diagnostic test for the early detection of lung cancer that allows stratification of individuals according to their risk of developing lung cancer.

According to the research presented at IASLC 2019 World Conference on Lung Cancer a combination of the EarlyCDT-Lung Test followed by CT imaging in Scottish patients at risk for lung cancer resulted in a significant decrease in late stage diagnosis of lung cancer and may decrease lung cancer specific mortality.

The test identifies 41% of lung cancers with a high specificity of 90%, compared to CT scanning, which identifies 67% of lung cancers but with a low specificity of around 49%.

In what is believed to be the largest trial of its kind in the world, Sullivan trialled the test on 12,208 smokers and former smokers from Glasgow, Tayside and Lanarkshire, aged between 50 and 75, who were deemed to be at a high risk of developing lung cancer over the next 24 months.

Test positive patients were offered a chest X-ray followed by a non-contrast thoracic CT scan. If the initial CT scan revealed no evidence of lung cancer then subsequent CT scans were offered six monthly for 24 months.

Individuals with abnormalities were followed up over the study period or referred for clinical care as appropriate.

All individuals entering the study were followed up via trial monitoring software linked to Scottish Health Records including the Scottish Cancer Registry.

Sullivan's team discovered that 127 lung cancers were diagnosed in the study period (56 in the intervention group and 71 in the control arm) and 9.8% of the intervention group had a positive EarlyCDT-Lung test and 3.4% of these were diagnosed with lung cancer in the study period.

The professor said: "The study was not powered to detect a difference in mortality after two years, however there was a non-significant trend suggesting fewer deaths in the intervention arm compared to the control.

"Similar results were noted relating to lung cancer-specific mortality."

Sullivan added that significantly fewer participants in the intervention group were diagnosed at a late-stage compared with the control group.

"Our results show that the combination of the EarlyCDT-Lung followed by CT imaging in those with a positive blood test, results in a significant decrease in late stage diagnosis of lung cancer and may decrease all cause and lung cancer specific mortality.

"We shall continue follow up of all participants' lung cancer and mortality outcomes at 5 years using Scottish ISD (Information Services Division) data to study these effects further."