London - A quick blood test for smokers could slash death rates from lung cancer, research suggests.
A British study involving 12 200 people found the test detected cancer more than four years before tumours showed up on scans.
The trial, led by scientists at the University of St Andrews, found far more people were diagnosed at an early stage of cancer using the blood test.
The research – presented at the World Conference on Lung Cancer in Barcelona – found that 41% of patients who received the blood test and then a CT scan were diagnosed at phase one or two, when tumours are still treatable.
For those who only received a CT scan following the arrival of symptoms – 27% were diagnosed at these stages.
Experts say early diagnosis is key to survival – allowing quicker treatment, better outcomes and fewer deaths.
Of the 6 087 people who received the blood test, 17 died within two years. There were 24 deaths among the 6 121 who did not receive the test.
Researchers say these numbers are too small to be certain that it will save lives, but they expect that after a few more years of follow-up they will see bigger numbers and a more significant difference.
Oncimmune, the UK firm behind the test, plans to submit its findings to the UK National Screening Committee.
The researchers believe that in future they will see similar results for other cancer types – including breast, prostate, liver and ovarian cancer.
Study leader Professor Frank Sullivan, of the University of St Andrews, said: "These landmark findings are likely to have globally significant implications for the early detection of lung cancer by showing how a simple blood test, followed by CT scans, is able to increase the number of patients diagnosed at an earlier stage of the disease, when surgery is still possible and prospects for survival much higher."
The test works by spotting antibodies which are produced as part of the body’s defence against cancer.
For each cancer type the antibodies are slightly different.
For lung cancer, the test picks up seven different antibodies.
The company’s liver test, which spots a different set of antibodies, was launched in May 2018 and tests for bowel, prostate, breast, ovarian and gastric cancer are in trials.