The addition of a biomarker blood test in a lung cancer screening program can increase the detection of early stage disease and may offer a more targeted approach, a UK study has shown.
An autoantibody blood test followed by imaging detected more stage I/II lung cancers in a high risk screening cohort and could potentially shift the diagnosis away from stage III/IV, according to researchers in Scotland.
In a randomised controlled trial of more than 12,000 high risk adults aged between 50 and 74, they showed that use of the EarlyCDT-Lung test followed by low dose CT in those with a positive result led to significantly fewer lung cancers diagnosed at a later stage.
Overall, 9.8% of those offered the blood test had a positive result and 3% (18) of those of these had a confirmed case of lung cancer within two years. Among those who tested negative 0.7% (38) were diagnosed with lung cancer during the study.
After two years of follow up, 127 lung cancers were detected in total, with 33 of 56 (58.9%) lung cancers in those who had the blood test were diagnosed at stage III/IV compared with 52 of 71 (73.2%) in controls who were treated per usual guidelines for detection of disease in symptomatic patients.
In all 325 people had to be screened to prevent one stage III/IV/unspecified lung cancer diagnosis, the researchers reported. The absolute risk reduction in stage III/IV disease was 0.3% for those who had the biomarker test compared with all participants and 14.3% when only including those who were diagnosed with lung cancer.
The EarlyCDT-Lung test can be used with finger prick or on whole blood and measures seven autoantibodies specific to a range of tumour-associated antigens.
Writing in the European Respiratory Journal, the researchers said this was the first phase IV evaluation of a blood-based biomarker panel for lung cancer and it shows a significant and ‘clinically important’ decrease in the incidence of advanced stage disease.
There were non-significant differences in lung cancer mortality (- 29.2% relative risk), and all-cause mortality (-19.4% ) after two years and longer follow up will be needed, they said.
In addition, questions remain around cost-effectiveness, the level of risk that should be targeted, the time interval between tests, and how to improve take up of those most at risk, they concluded.
Speaking with the limbic, study leader Professor Frank Sullivan, Professor of Primary Care Medicine at the University of St Andrews said the findings were potentially very important if confirmed by longer follow up of the patients.
“We have the three-year data and should have all the governance in place to analyse that soon.
He added: “A phase V study – a cluster RCT in 60-70K subjects – is being planned to determine whether offering the blood test first works better than sending potential study subjects a questionnaire to determine eligibility for LDCT.”