Causes of lung cancer

While the causes of lung cancer are not fully understood, there are a number of risk factors associated with developing the disease. These factors include:

Age – Lung cancer is most commonly diagnosed in people aged 60 years and older.

Family history – Having family members who have been diagnosed with lung cancer increases your risk.

Personal history – The risk of developing lung cancer is increased if you have been previously diagnosed with lung diseases such as lung fibrosis, chronic bronchitis, emphysema, and pulmonary tuberculosis.

Tobacco smoking – About one in 10 smokers develop lung cancer. Studies from a number of countries suggest that a life-long smoker has between a 10 and 20% risk of developing lung cancer. However, compared with non- smokers, smokers are more than 10 times more likely to develop lung cancer. In Australia about 90% of lung cancer cases in males, and 65% in females, are estimated to be a result of tobacco smoking.

The risk of lung cancer among smokers is strongly related to the length of time and the number of cigarettes a person has smoked.

Passive smoking – Breathing in someone else’s tobacco smoke (passive or secondhand smoking) can cause lung cancer.

Non-smokers who have been frequently exposed to secondhand smoke are 20–30% more likely to develop lung cancer than non-smokers who have not been exposed. People who have never smoked and have not been around secondhand smoke have about a 0.5% risk of developing lung cancer.

Exposure to asbestos – Although the use of asbestos has been banned nationally since 2003, it may still be in some older buildings. People who are exposed to asbestos have a greater risk of developing cancer. Some people are exposed to asbestos at work or during home renovations. People who have been exposed to asbestos and are, or have been, a smoker are at even greater risk.

Exposure to other elements – Contact with the processing of steel, nickel, chrome and coal gas may be a risk factor. Exposure to radiation and other air pollution, such as diesel fumes, also increases the risk of lung cancer.

If you are concerned about your risk factors, talk to your doctor.

If you are a smoker

If you need help quitting, call Quitline on 13 78 48.

Smoking is addictive and this is the main reason people continue to smoke even though many may be concerned about the risks or have tried to quit. Your doctors understand this and will consider it when caring for you. They shouldn’t regard you negatively because you are (or were) a smoker.

This information was last reviewed in December 2014
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