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What are the risk factors?

The causes of lung cancer are not fully understood, and some people develop lung cancer without having any known risk factors. The factors listed below are known to increase the risk of developing the disease. Having these risk factors does not mean you will develop lung cancer, but if you are concerned about your risk, talk to your doctor.

Tobacco smoking – In Australia, about 90% of lung cancer cases in men and 65% in women are estimated to be a result of smoking tobacco. The earlier a person starts smoking, the longer they smoke and the more cigarettes they smoke, the higher the risk of developing lung cancer. However, about 1 in 5 people (21%) who are diagnosed with lung cancer have never been smokers.

Second-hand smoking – Breathing in other people’s tobacco smoke (passive or second-hand smoke) can cause lung cancer. Living with a smoker increases a nonsmoker’s risk by up to 30%.

Exposure to asbestos – People who are exposed to asbestos are more likely to develop lung cancer or pleural mesothelioma. Although the use of asbestos in building materials has been banned across Australia since 2004, there is still asbestos in some older buildings and fences.

Exposure to other elements – People exposed to radioactive gas (radon), such as uranium miners, have an increased risk of lung cancer. Air pollution is another  risk factor. Contact with the processing of arsenic, cadmium, steel and nickel, and exposure to diesel in the workplace may also be risk factors.

Family history – You may be at a higher risk if a family member has been diagnosed with lung cancer.

Personal history – Having another lung disease (e.g. lung fibrosis, chronic bronchitis, pulmonary tuberculosis, emphysema) or human immunodeficiency virus (HIV) may increase the risk of lung tumours.

Older age – Lung cancer is most commonly diagnosed in people over the age of 60 years, although it can occur in younger people.

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This information is reviewed by

This information was last reviewed in October 2020 by the following expert content reviewers: A/Prof Nick Pavlakis, President, Australasian Lung Cancer Trials Group, President, Clinical Oncology Society of Australia, and Senior Staff Specialist, Department of Medical Oncology, Royal North Shore Hospital, NSW; Dr Naveed Alam, Thoracic Surgeon, St Vincent’s Private Hospital Melbourne, VIC; Prof Kwun Fong, Thoracic and Sleep Physician and Director, UQ Thoracic Research Centre, The Prince Charles Hospital, and Professor of Medicine, The University of Queensland, QLD; Renae Grundy, Clinical Nurse Consultant – Lung, Royal Hobart Hospital, TAS; A/Prof Brian Le, Director, Palliative Care, Victorian Comprehensive Cancer Centre – Peter MacCallum Cancer Centre and The Royal Melbourne Hospital, and The University Of Melbourne, VIC; A/Prof Margot Lehman, Senior Radiation Oncologist and Director, Radiation Oncology, Princess Alexandra Hospital, QLD; Susana Lloyd, Consumer; Caitriona Nienaber, 13 11 20 Consultant, Cancer Council WA; Nicole Parkinson, Lung Cancer Support Nurse, Lung Foundation Australia.