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ECLS Study

Early detection of Cancer of the Lung Scotland (ECLS)

Frequently Asked Questions

Frequently Asked Questions 

Who was in the study?  12,209 people who had a higher risk, than other people of the same age, of developing lung cancer. The risk factors for ECLS participants were:

·        Being aged 50-75

·        Smokers and ex-smokers

·        Having a close relative with lung cancer. 


What happened to the people in the study? 12,209 were randomly allocated to either the test group or to usual clinical care, the no-test control group (displayed on Flowchart 1: ECLS 


What was the test?  The EarlyCDT® Lung test has been developed as a simple blood test for the early detection of lung cancer. The test involved taking a small sample of blood and looking for proteins that are linked to lung cancer. If these proteins were detected above a set level, it was considered to be a positive test result. If low-level or no proteins were detected, it was considered to be a negative test result. The results give us information about the risk of a cancer being present over the next two years.

How many people had a positive test?  The EarlyCDT Lung blood test was taken by 6088 test group participants:

  • 5490 (90.2%) had a negative test result
  • 598 (9.8%) had a positive test result.  The people with a positive test result went on to have a baseline chest X-ray and CT-scan, then 6-monthly CT scans for up to 2 years.

Are the study findings helpful?  The ECLS study showed that the EarlyCDT Lung blood test helps to detect lung cancer when it is still in an early stage. The test is also very good at telling that someone does not have lung cancer. Measuring a group of proteins, known as autoantibodies, has the potential to detect lung cancer in its early stages of development, when there are more treatment options available and a greater potential for better outcomes.

Can the test find other cancers?  Test is not optimised for other cancers; however, there could be some crossover, hence we ask everyone to continue with their age/gender appropriate cancer screening.

How successful was the study?  The study showed that the EarlyCDT Lung test is successful at helping to find lung cancer before any symptoms in people who are at increased risk.  People who had the EarlyCDT Lung test were less likely to develop more advanced, late stage lung cancer later in the study (displayed on Graph 1: Test accuracy & late stage cancers). This means they can receive treatment at an earlier stage when it is more likely to be effective.

Will everyone in the positive group develop cancer?  The EarlyCDT Lung blood test is very good at making sure that no cases of lung cancer are missed. Out of a hundred people who had a negative result on their blood test, ninety-nine did not develop lung cancer in the two-year follow-up period.  At the same time, a positive test result does not always mean a diagnosis of lung cancer. A positive result can be seen as a reason to do further tests to find out more.

Is this test like any other cancer screening test?  Out of every thirty three people who tested positive, only one person actually had lung cancer (1 in 33) diagnosed within two years.  This level of success is similar to the breast cancer screening programme (1 in 26).

What about nodules and cancer risk?  Lung nodules are common in the group of patients we studied. Further research is underway to be clearer on how a positive or negative test result affects the chances of a lung nodule being a cancer.

Will ECLS participants be offered re-testing?  We would like to do this but need to obtain more research funding first.  We plan to speak to ECLS participants to find out if they would like to be offered re-testing. 

Did the study help people to give up smoking?  Participants of the ECLS study who smoked could join an NHS programme to help them quit. Graph 2: Risk of Lung Cancer as Ex-smoker shows the risk for smokers and ex-smokers, with less risk the younger someone stops smoking. People in the test group who had the EarlyCDT Lung blood test, regardless of the test result, were twice as likely to take up this offer as those who did not have the test.  

Where and when will results be published and can I see them?  A summary of the study findings will be presented on the 9th of September, 2019, to the World Lung Cancer Conference. There will be a press release on this day.   Close to the 9th of September, everyone who took part will be sent a summary of the study findings.   At this time, we are not able to say when and where the main results will be published. As soon as the scientific publication happens, there will be newspaper, radio and television press releases. The ECLS study website will also be updated as soon as this happens.

Will there be a national scheme for early detection?  With these positive outcomes for the ECLS study, the next step is to explore the possibility rolling-out the EarlyCDT Lung test on a bigger scale. This could take the form of a screening programme, similar to the bowel cancer screening program. Another option may be to offer the test to people who are at increased risk of developing lung cancer. We plan to speak to ECLS participants to seek their views.

ECLS shows that blood-based testing, such as the EarlyCDT Lung test, may have an important role in future lung cancer screening programmes. Further testing is needed to find out the best timing for the blood test, and to improve the engagement of patients at the highest risk of lung cancer. 

If you have any further questions please contact us