Patients and the public

What is lung cancer?

Cancer develops when cells become abnormal and grow out of control. Over time they form a clump - also known as a tumour. Lung cancer develops in the tubes that carry air in and out of the lungs (your airways) or within the lung. It can then spread outside the lung. About 40,000 people develop lung cancer each year in the UK.

Lung cancer often develops slowly. It is thought that cells first become abnormal at least five years before the cancer can be detected. By the time lung cancer is diagnosed, it has often spread outside the lung. If this happens, the cancer is rarely cured. The reasons for this delay include:

  • most tumours grow slowly
  • the lungs are large
  • the lungs do not feel pain
  • some of the symptoms are similar to those of other lung problems such as bronchitis or chronic obstructive pulmonary disease (COPD) (restricted airflow to the lungs)

By the time lung cancer is diagnosed, it has often spread outside the lung. If this happens, the cancer is rarely cured. The UKLS aims to show that finding lung cancer at a very early stage means that it can be treated successfully. For more information about lung cancer see:

Who is at risk of developing lung cancer?

Anybody can develop lung cancer, but people who smoke (or used to smoke) are most at risk. The risk increases with the total number of cigarettes you smoke. If you stop smoking, the risk gets less over time. Passive smoking (breathing in someone else’s smoke) over a long period of time may also cause lung cancer. Some people develop lung cancer as a result of breathing in asbestos which is even more of a risk if they smoke as well. Lastly people who have never smoked or had little exposure to cigarette smoke can develop lung cancer (usually of a type called adenocarcinoma) although this is much less common.


What is Lung Cancer Screening?

Lung cancer screening uses an advanced x-ray technique, called computed tomography (CT) scanning, in order to find lung cancer before symptoms develop, so that early treatment can remove the cancer and deaths from lung cancer may be prevented. More people die from lung cancer in the UK every year than from any other form of cancer. Finding lung cancer by screening instead of symptoms may mean that treatment is more effective. Lung cancer screening aims to find changes in the lung at the time of the scan but it cannot prevent you from getting lung cancer in the future.


Why is a trial so important?

If we can find a way to diagnose lung cancer at an early enough stage to be cured we will save many lives. There are National projects that help people to be aware of symptoms of cancer, including lung cancer that may be effective, but this will only be able to pick up lung cancer when symptoms have developed and the cancer is quite large. Screening can pick up lung cancer very early in comparison. For the National Early Diagnosis and Awareness Initiative (NAEDI) see

The trial is important because as well as the likely benefits, there are potential risks of screening. The CT scans use a small amount of radiation that can itself be harmful. Scans also pick up other abnormalities that are not cancer that have to be looked into. This can cause people to worry and sometimes biopsies have to be done to make a firm diagnosis. We also need to know if screening is cost effective enough to be possible in the NHS.


Have any other trials shown CT screening to work?

So far only one trial that was done in the USA has shown a definite benefit of screening. This was called the National Lung Cancer Screening Trial and involved over 50,000 people.  The deaths from lung cancer were reduced by one fifth by CT screening. We do not yet know how cost effective screening was in this trial.


Is screening available now?

In the UK screening is not currently available as we do not know it is effective in the UK. Some private organisations may choose to offer this but people who are considering this should be careful to get as much information as possible first. UKLS have produced a statement that sets out the current situation and includes advice to professionals who may want to offer screening.

When will the results be available?

The preliminary pilot (4200 subjects) results will be available in 2013. The full study will first report in 2016.


Can I take part in the UKLS trial?

You can only take part in the UKLS trial if you have been invited to by the UKLS researchers. The trial is currently running in Liverpool and Cambridge but not everyone will be invited, only a proportion of the population.  It is important that the trial protocol is followed so that we can rely on the results we find.