Disease and Drug Information

Causes and Risk Factors of Lung Cancer

Lung Cancer Risk Factors

Several risk factors can leave you more susceptible to developing lung cancer. Smoking, exposure to radon and asbestos, and personal and family history, are some of the top risk factors that contribute to lung cancer.

Tobacco Use

Tobacco use is the number one risk factor for lung cancer, with roughly 80-85% of lung cancers being linked to cigarette smoking here in the U.S. That risk goes up with the number of years and packs per day. Quitting--no matter what your age--can significantly lower your risk of developing lung cancer.

Lung cancer is also linked to cigar and pipe smoking, however, the risk may be lower in people who do not also smoke cigarettes. This of course varies based on level of inhalation and quantity smoked per day.

Many people think that electronic cigarettes (vapes) are a safer alternative to traditional cigarettes, however, there is still not enough evidence to support that claim. Not only is it unclear if e-cigarettes work well to help people stop smoking, the ingredients used in vapes are questionable as to whether or not they pose a health threat to those inhaling them. While they may not be as harmful as traditional cigarettes, the best option is quitting all smoking-related habits.

People who don’t even smoke at all can still have an increased risk if they inhale the smoke of others. This smoke from other people’s cigarettes, pipes, or cigars is called secondhand smoke. In 2006 the Surgeon General published a report that stated there is no risk-free level of exposure to secondhand smoke. Living with a smoker increases a non-smoker's chances of developing lung cancer by 20-30%.

Radon Exposure

Radon is a naturally-occurring radioactive gas that results from the breakdown of uranium in soil and rocks. It is odorless, colorless, and tasteless, making it very hard to detect. These gases can seep into various areas including building foundations, living spaces, and working spaces. Cigarette smoking combined with radon exposure seriously increases the risk of lung cancer. According to the US Environmental Protection Agency (EPA), radon is the second leading cause of lung cancer among Americans and the leading cause of lung cancer in non-smokers.

You can visit the Arizona Department of Health Services’ website for further information on radon risks in Arizona.

Exposure to Asbestos

Asbestos refers to a set of six naturally occurring fibrous minerals: chrysotile, crocidolite, amosite, anthophyllite, tremolite, and actinolite. It has been used in a number of different commercial and industrial capacities including roofing shingles, floor tiles, textile products and automotive parts for decades. While the dangers of asbestos exposure are well-known now, there was a time when people were regularly exposed without protection. People who have worked with asbestos, especially without protective gear, are several times more likely to develop mesothelioma, a type of cancer that starts in the pleura (the lining surrounding the lungs). The lung cancer risk is much greater in workers exposed to asbestos who also smoke tobacco.

Personal or Family History

If you are a lung cancer survivor, there is a risk that you may develop lung cancer again, especially if you smoke. Your risk of lung cancer may also be higher if your parents, siblings, or children have had lung cancer--especially if the relative was diagnosed at a younger age. It is unclear how much of the risk is due to shared genes and how much may be from exposure to environmental hazards like tobacco smoke and asbestos or exposure to substances such as radon, chromium, and nickel. There are, however, some instances when genetic testing may be appropriate. Talk to your oncologist or one of our genetic counselors at Arizona Oncology about whether you are a candidate for lung cancer genetic testing.

Other Lung Cancer Risk Factors

There are also other factors such as substances, exposures, and lifestyle situations that can increase your risk of lung cancer. Some of these can include:

  • Age
  • Exposure to arsenic, diesel exhaust, and other chemicals or minerals such as silica, uranium, and chromium
  • Previous radiation therapy to the chest
  • Air pollution

Most cases of lung cancer are preventable. By avoiding exposure to risk factors, you can significantly limit your chances of developing lung cancer. 

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