Causes and risk factors

Each year over 38,000 people in the UK are diagnosed with lung cancer.

Cigarette smoking is known to be the cause of most lung cancers. Lung cancer has always been more common in men, particularly those over 40, as more men used to smoke than women. However, as more women have started smoking, the number of women developing lung cancer has gone up considerably.

People who don’t smoke can also develop lung cancer, although this is much rarer.

Other risk factors include exposure to asbestos, radon gas and – in very rare cases – substances such as uranium, chromium and nickel.

Lung cancer is not infectious and can’t be passed on to other people.

Smoking Back to top

The more you smoke, the greater your risk of developing lung cancer. Lung cancer is also more likely to develop in people who start smoking at a young age. Filtered and low-tar cigarettes may slightly reduce a person’s risk of developing cancer, but the risk is still far greater than that of a non-smoker.

Stopping smoking

If a person stops smoking, the risk of lung cancer falls quite quickly. After about fifteen years, that person’s chances of developing the disease are similar to those of a non-smoker.

Passive smoking

It now appears that breathing in other people’s cigarette smoke (passive smoking) slightly increases the risk of lung disease and cancer. The risk is still much less than if you smoke yourself.

Pipes and cigars

Although pipe and cigar smokers have a lower risk of lung cancer than cigarette smokers, they are still at a much greater risk than non smokers.

Cannabis

Smoking cannabis may also increase the risk of developing lung cancer. Although less is known about the harmful effects of smoking cannabis, it is believed to cause similar damage to the cells in the lungs as smoking tobacco.

Genetic risk Back to top

In some families, smokers may be more likely to develop lung cancer due to inherited faulty genes.

Age Back to top

The risk of getting lung cancer increases with age. It’s rare for a person to be diagnosed with lung cancer before the age of 40 years. More than 85 out of every 100 people with lung cancer are over the age of 60.

Asbestos Back to top

People who have been in prolonged or close contact with asbestos have a higher risk of lung cancer, especially if they smoke. Asbestos and tobacco smoke act together to increase the risk. Many people have been in contact with asbestos during their working lives. Low-level exposure increases the risk of lung cancer only slightly (compared to the risk from smoking), while heavy exposure may result in a much higher risk.

Asbestos exposure also increases the risk of mesothelioma|, a cancer of the membranes which cover the lungs. If you have worked with asbestos and developed lung cancer, you may be able to claim compensation| or be paid Industrial Injuries Disablement Benefit. You can get more advice about this from your cancer doctor or from support organisations|. 

Radon gas Back to top

In some parts of the UK, such as the West Country and the Peak District, a naturally occurring gas called radon can pass from the soil into the foundations of buildings. It is now thought that in high concentrations this gas may increase the risk of developing lung cancer. If you’re worried about the level of radon in your house, you can get a radon detector from the radiation protection division of the Health Protection Agency|. They can also advise you on what you can do to reduce the risk.

Other causes Back to top

Contact with certain chemicals and substances – such as uranium, chromium and nickel – can cause lung cancer, but these are very rare causes. Air pollution has been suggested as a cause of lung cancer, but this is difficult to prove.