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Macmillan and Cancerbackup merged in 2008. Together we provide free, high quality information for people affected by cancer through our publications, website and phone service. Find out more|.
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Lung cancer is the second most common cancer diagnosed in the UK. Approximately 39,000 people are diagnosed each year.
Cigarette smoking is the cause of most lung cancers, but there are a number of other risk factors and causes that can increase your chance of developing the disease.
A risk factor is something that increases your chance of developing a health condition. For example, age is a risk factor for many cancers – most people who develop cancer are over 65. But having a particular risk factor doesn’t mean you’ll definitely get cancer, and people without any known risk factors can still develop it.
Lung cancer has always been – and still is – more common in men, as more men used to smoke than women. However, the number of men diagnosed with lung cancer in the UK has been falling over the last 30 years. And, as more women have started smoking, the number of women developing lung cancer has increased.
People who don’t smoke can also develop lung cancer. Approximately 10–15% of people who get lung cancer will never have smoked.
Other risk factors include the effects of past cancer treatment, and 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.
The more you smoke, the greater your risk of developing lung cancer. It's 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.
If someone stops smoking, their risk of developing lung cancer falls quite quickly. After about 15 years, their chance of developing the disease is similar to that of a non-smoker.
It now appears that breathing in other people’s cigarette smoke (passive smoking) slightly increases the risk of lung disease and cancer. But the risk is still much less than if you smoke yourself.
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.
Smoking cannabis may also increase the risk of developing lung cancer. Less is known about the harmful effects of smoking cannabis, but it's believed to cause similar damage to the cells in the lungs as smoking tobacco.
In some parts of the UK, such as the South West and the Peak District, a naturally occurring gas called radon can pass from the soil into the foundations of buildings. Exposure to high concentrations of radon can increase the risk of developing lung cancer. It’s believed that approximately 9% (9 in 100) of lung cancers in European countries are caused by exposure to radon.
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.
Like most types of cancer, lung cancer is more common in older people. About 80% (8 in 10) of lung cancers are diagnosed in people over 60. Lung cancer rarely affects people under 40.
Some people with a close relative who has had lung cancer may be at an increased risk of it themselves, although the increase in risk is very small. Your risk is slightly greater if your relative was a non-smoker and if they developed lung cancer at an early age, or if you have more than one relative on the same side of the family who developed lung cancer.
If you’re concerned about a family history of lung cancer, you might find it helpful to read our more detailed information about genetic risk|. You can also talk to your GP.
People who have been in prolonged or close contact with asbestos have a higher risk of developing 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.
If you have worked with asbestos and develop 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, from support organisations|, or by calling our cancer support specialists|.
Asbestos exposure also increases the risk of mesothelioma |, a cancer of the membranes which cover the lungs.
People who have been treated for some types of cancer may have a slightly increased risk of developing lung cancer many years later. Women who were treated with radiotherapy for breast cancer and who smoke may have an increased risk of lung cancer. People who have been treated for some types of lymphoma using radiotherapy to the chest area, and men who have been treated for testicular cancer using radiotherapy to the chest area, have a slightly increased risk of lung cancer, especially if they smoke. However, the risk of developing lung cancer is far outweighed by the benefits of the initial treatment.
Contact with certain chemicals and substances - such as uranium, chromium and nickel - can cause lung cancer, but this is rare. Air pollution has been suggested as a cause of lung cancer, but this is difficult to prove.
Exercise may help to reduce the risk of lung cancer. A diet containing lots of fresh vegetables may also help to reduce the risk, but only for people who smoke.
For answers, support or just a chat, call the Macmillan Support Line free (Monday to Friday, 9am-8pm)
If you have any questions about cancer, need support or just want someone to talk to, ask Macmillan.