Causes of Lung Cancer

• Smoking is the leading cause of lung cancer.¹
• Exposure to radon is the second leading cause of lung cancer, and the leading cause in people who have never smoked.²
• Other risk factors include:¹
    - lung scarring from tuberculosis
    - occupational or environmental exposure to:
       • secondhand smoke
       • radiation
       • asbestos
       • air polution
       • arsenic
       • some organic chemicals

• Genetic predisposition may also play a role in lung cancer development.¹
• Between 20,000 to 30,000 people who have never smoked are diagnosed with lung cancer in the U.S. each year.³
• At least 43% of all lung cancers are diagnosed in people who have already quit smoking.⁴  As the number of people who have quit smoking increases, this percentage will continue to grow.⁵
• Although quitting smoking greatly reduces the risk of lung cancer, a significant risk can remain for up to 30 years.^6,7

References

1 American Cancer Society. Cancer Facts and Figures 2011. Atlanta: American Cancer Society; 2011.
2 National Research Council. Health Effects of Exposure to Radon: BEIR VI. National Academy Press,
Washington, DC, 1999.
3 Thun, MJ, et al. Lung Cancer Occurrence in Never-Smokers: An Analysis of 13 Cohorts and 22
Cancer Registry Studies. PLOS Medicine, 2008. 5(9): e185. Doi:10.1371/journal.pmed.0050185
4 Tong, L, et al. Lung carcinoma in former smokers. Cancer, 1996. 78(5): 1004-1010.
5 Burns DM. Primary prevention, smoking, and smoking cessation: Implications for future trends in
lung cancer prevention. Cancer, 2000. 89:2506–2509.
6 Satcher, D, Thompson, TG and Kaplan, JP. Women and smoking: a report of the Surgeon General.
Nicotine Tob Res, 2002. 4(1): 7-20
7 Ebbert, JO, et al., Lung cancer risk reduction after smoking cessation: observations from a
prospective cohort of women. JClin Oncol, 2003. 21(5): 921-926.