Many factors can increase the risk of developing lung cancer, but it doesn’t mean that any one of these factors will definitely lead to lung cancer — just that each factor increases risk to a different degree.


Smoking is the leading risk factor associated with lung cancer, with over 80 percent of cases believed to be caused by tobacco. A smoker is many times more likely to develop lung cancer than a non-smoker, and is more likely to get the more aggressive forms of lung cancer that have poor prognosis, such as small cell lung cancer (SCLC). The more cigarettes someone smokes, and the longer he or she remains a smoker, the higher that person’s risk — and cigars are no safer than cigarettes. Smoking can also increase the risk of lung cancer associated with other risk factors such as radon and asbestos exposure.

Breathing in second-hand smoke can also increase the risk of lung cancer, especially over a prolonged period.


Radon gas exposure is one of the leading causes of lung cancer in non-smokers. Radon is naturally produced by the gradual breakdown of tiny amounts of uranium present in the soil, rocks and water into a gas that may accumulate in buildings. Some areas of the world have higher levels of radon gas than others, and levels can be monitored using store-brought kits.

Carcinogens and pollution

A number of carcinogens can increase cancer risk. One example is asbestos, a substance that was once widely used in construction for its fire-retardant qualities. Asbestos is now tightly regulated but it is still present in many buildings. When inhaled, asbestos can raise the chance of developing lung cancer or mesothelioma. People who work with carcinogens such as radioactive ores or chemicals like arsenic, silica and nickel are also more likely to get lung cancer.

Exhaust fumes produced by diesel cars has been linked an increased risk of cancer which varies depending on daily pollution levels.

Radiation therapy

Patients who have been treated with radiation therapy near the lungs (for example, for Hodgkin lymphoma) are at a slightly higher risk of developing lung cancer, since the radiation is not limited solely to the targeted area.

Genetic risk factors

People with a family history of lung cancer may also be more likely to develop it themselves.

Mutations in certain genes — either those inherited from parents or occurring during one’s lifetime — can increase the risk of cancer. These genes often help regulate cell growth, division or death and a malfunction causes these cells to go out of control and multiply uncontrollably. Mutations can occur randomly or be caused by certain substances such as tobacco smoke.

Mutations accumulate over time, resulting in a higher chance of developing cancer with age.

Note: Lung Cancer News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.