Over the years there have been many studies to try and detect lung cancer at an early stage, before it causes any symptoms. If it were possible to do this it would be likely to improve survival, as people with lung cancer that is detected early do much better than those where the lung cancer is found at a later stage. The trials have almost all looked at smokers, who are the people most likely to be at risk of developing lung cancer.

These screening trials have used either regular chest x-rays or analysing sputum (phlegm) samples for cancer cells or a combination of these two tests.

Although some of the trials have suggested that regular tests may lead to slightly earlier diagnosis of a cancer there is no evidence in any study that this produces a better outcome from treatment or any improvement in cure rates or survival. This is because the tests used were not sensitive enough to detect the lung cancer at a sufficiently early stage to affect survival.

As a result of these findings there is universal agreement that regular chest x-rays or analysing sputum to detect lung cancer are of no value. So having a yearly chest x-ray really isn't likely to help you.

Current research is looking at using more sensitive tests such as low dose CT scans to see if these will be more effective at detecting lung cancer at an earlier, more curable stage, but it will be some time before we know if this approach is more successful.

I am afraid the best advice is 'stop smoking'!