A study using a blood test to detect lung cancer (ECLS)

Cancer type:

Lung cancer





This study looked at using a blood test to try and detect lung cancer. It was for people with an increased risk of developing lung cancer.

The study was open for people to join between 2013 and 2016. The team reported the results in 2020.

More about this trial

Treatment for lung cancer is usually more successful if the cancer is diagnosed early. So doctors and researchers are looking at ways of diagnosing lung cancer earlier.

In this study, they looked at a blood test for people who are at risk of lung cancer. It is called the EarlyCDT-lung test. They hoped it would show antibodies in the blood when the cancer is at a very early stage. Antibodies are part of our immune system.

Researchers wanted to see how well the test works. The took blood samples from people who were at an increased risk of developing lung cancer.

The main aim of this study was to find out how good the test is at detecting early stage lung cancer.

Summary of results

Study design
The research team identified more than 12,000 people in Scotland who had an increased risk of developing lung cancer. This included people who:

  • were over 50
  • smoked
  • had worked with asbestos
  • had a family history of lung cancer

They were put into 2 groups at random:

  • half had the EarlyCDT-lung blood test
  • half had standard care 

The people who had the Early CDT-lung test went on to have an x-ray and CT scan if the test was positive. This means it showed there were specific antibodies in the blood.

The people who had usual care had standard tests and scans if they had any symptoms of lung cancer.

The research team looked at the number of people who were diagnosed with lung cancer within 2 years of joining the study. 

They found it was higher for those who had a positive EarlyCDT-lung blood test:

  • 18 out of 598 people (3.0%) who had a positive blood test
  • 38 out of 5,489 people (0.7%) who had a negative blood test
  • 71 out of 6,121 people (1.2%) who had standard care

They also looked at what stage people’s cancer was at diagnosis. This means how big it was and whether it had spread to another part of the body.

They found that lung cancer was more likely to be diagnosed at an earlier stage if people had a positive EarlyCDT-lung test. This is compared to people who had a negative test and people who had standard care.

The research team concluded that having an EarlyCDT-lung blood test could help diagnose lung cancer at an earlier stage. They suggest more work is done.

The team plan to do more analysis on this study, and we hope to update this page once more information is available.

More detailed information
There is more information about this research in the links below. 

Please note, this information may not be in plain English. Some of it has been written for health care professionals and researchers.

Earlier diagnosis of lung cancer in a randomised trial of an autoantibody blood test followed by imaging 
F Sullivan and others 
European Respiratory Journal, 2021. Volume 57, Issue 1.

ECLS Study Findings
ECLS Study website
Accessed January 2022

Where this information comes from    
We have based this summary on the information in the links above. Some of this has been reviewed by independent specialists (peer reviewed Open a glossary item) and published in a medical journal. We have not analysed the data ourselves. As far as we are aware, the links we list above are active and the information is free and available to view.

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Professor Frank Sullivan

Supported by

Chief Scientist Office (CSO)
NHS Tayside
NIHR Clinical Research Network: Cancer
University of Dundee

If you have questions about the trial please contact our cancer information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:


Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Over 60,000 cancer patients enrolled on clinical trials in the UK last year.

Last reviewed:

Rate this page:

Currently rated: 4 out of 5 based on 1 vote
Thank you!
We've recently made some changes to the site, tell us what you think