There is no national screening programme for lung cancer in the UK. Find out why this is and about research into this subject.
What screening is
Screening means testing people for early stages of an illness before they have any symptoms. For screening to be useful the tests:
- must be reliable at picking up the illness
- must be simple and quick
- overall must do more good than harm to people taking part
Why there is no national lung cancer screening programme
There is no national screening programme for lung cancer in the UK. This is because:
- it isn't clear that screening can save lives from lung cancer
- the tests have risks
- they can be expensive
Low dose CT scans are being looked as a possible screening test for lung cancer. Tests like this have risks. The lungs are very sensitive to radiation and frequent scans might cause lung damage.
Tests can also find lung changes that look like cancer and need to be checked by further tests, such as a biopsy. These further tests can also have risks.
Lung screening might also cause overdiagnosis. Overdiagnosis means that some lung cancers found through screening might never become life threatening. So it is possible that some people go on to have lung cancer treatment that they would never have needed. And of course they have the side effects and anxiety that anyone having cancer treatment goes through.
Researchers need to balance the benefits of a possible screening programme with the risk of overdiagnosis.
What to do if you think you're at risk
Talk to your GP if you think you are at higher than average risk of lung cancer.
Researchers are checking whether it is possible to screen groups of people at high risk of developing lung cancer. These include:
- people who smoke, or used to smoke for many years
- people who have chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease (COPD) includes lung diseases such as chronic bronchitis and emphysema.
It is likely to be more cost effective to screen people at high risk, rather than to screen everyone.
Researchers are also trying to develop better tests to find lung cancer early.
Research into lung cancer screening
Spiral CT scan
Spiral CT scanning is also called low dose helical CT. It uses lower doses of radiation compared to standard CT scans.
The National Lung Screening Trial (NLST) involved more than 50,000 people in the USA and reported in 2011. The trial used spiral CT scans to screen people with no lung cancer symptoms who had smoked the equivalent of 20 cigarettes a day for 30 years.
It found that spiral CT scanning reduced the number of people who died from lung cancer. But it also found that some people were overdiagnosed. These means that some people were diagnosed and treated for a lung cancer which would not have caused them harm in their lifetime. There is no way to know which cancers are overdiagnosed. So these people go on to have cancer treatment that they would never have had, if they weren't screened.
The UK Lung Screening Trial also used spiral CT to screen current and ex-smokers for lung cancer. It found that spiral CT scans could diagnose lung cancer early. But more research is needed to find out whether a programme like this can save lives. As it was a small study, it couldn't publish results about how many people died of lung cancer.
A similar but larger trial is also taking place in the Netherlands and Belgium (the NELSON trial). The combined results of this trial and the UK Lung Screening Trial might help researchers understand more about using spiral CT scanning in lung cancer screening.
Researchers have also been looking into a new way of carrying out a test called a bronchoscopy in people at high risk of lung cancer. This is called fluorescence bronchoscopy and uses blue and white light to examine the lining of the airways.
A UK fluorescence bronchoscopy trial compared this type of bronchoscopy to standard bronchoscopy. It found that fluorescence bronchoscopy is better at showing changes in the lining of the airways that might become lung cancer. More research is being carried out to see whether this is a helpful test to use as part of lung screening.
Fluorescence bronchoscopy and spiral CT scan
A UK trial called the Lung-SEARCH study is looking at using both a spiral CT scan and fluorescence bronchoscopy. The trial is trying to find lung cancer at a very early stage in people with chronic obstructive pulmonary disease.
Chemical changes in the body
The MEDLUNG study is looking for substances in the body (biomarkers) that could show that lung cancer is developing before the person has any symptoms. It is for people who are at high risk.
People in the MEDLUNG study are having tests because they have symptoms that could be due to lung cancer. The researchers look at samples of sputum to see if there are changes in the cells. The aim is to find a biomarker that doctors might be able to use in the future to screen people for lung cancer.