A risk factor is any factor that is associated with increasing someone’s chances of developing a certain condition, such as cancer. Some risk factors are modifiable, such as lifestyle or environmental risk factors, and others cannot be modified, such as inherited factors and whether someone in the family has had cancer.
Having 1 or more risk factors does not mean that you will develop cancer. Many people have at least 1 risk factor but will never develop cancer, while others with cancer may have had no known risk factors. Even if a person with cancer has a risk factor, it is usually hard to know how much that risk factor contributed to the development of their disease.
Factors that are associated with a higher risk of developing lung cancer include:
- smoking cigarettes, pipes or cigars currently or in the past – this is the greatest risk factor for lung cancer, and the risk is greatest for people who began smoking early in life, smoked for longer and smoked more often; in particular, someone who has never smoked is very unlikely to develop small cell lung cancer
- exposure to secondhand smoke
- personal or family history of lung cancer
- radiotherapy treatment to the chest
- exposure to radon, a naturally occurring radioactive gas that can build up inside houses in some areas
- exposure to asbestos fibres– this also increases the risk of developing mesothelioma, which starts in the lining surrounding the lungs (the pleura) and is not considered a type of lung cancer
- exposure to other workplace substances, including radioactive ores (e.g. uranium), chromium compounds, nickel, arsenic, soot, tar or diesel fumes
- exposure to air pollution
- infection with HIV, the virus that causes AIDS
- a history of certain diseases of the lungs, including tuberculosis, fungal infections of the lungs, chronic obstructive pulmonary disease and pulmonary fibrosis.
Find out more about:
- Risk factors for lung cancer: an overview of the evidence
Based on a systematic review of the international literature, Risk factors for lung cancer: an overview of the evidence, provides information about lung cancer risk associated with active and passive tobacco smoking, environmental and occupational exposures and the role of family history.
- Cancer Australia Position Statement: Lifestyle risk factors and the primary prevention of cancer
American Cancer Society. Non-small cell lung cancer.
National Comprehensive Cancer Network (2014). NCCN guidelines for patients: non-small cell lung cancer, version 1.2014.
National Cancer Institute (2015). Non-small cell lung cancer treatment (PDQ®), patient version.
American Cancer Society (2015). Small cell lung cancer.
National Cancer Institute (2015). Small cell lung cancer treatment (PDQ®), patient version.
Cancer Australia (2012). Investigating symptoms of lung cancer: a guide for GPs.