NetWellness is a global, community service providing quality, unbiased health information from our partner university faculty. NetWellness is commercial-free and does not accept advertising.
Monday, September 25, 2017
Tobacco smoking is the most important risk factor for lung cancer. Cigarette, cigar, and pipe smoking all increase the risk of lung cancer. Tobacco smoking causes about 9 out of 10 cases of lung cancer in men and about 8 out of 10 cases of lung cancer in women.
Studies also show that the risk of lung cancer from smoking cigarettes increases with the number of cigarettes smoked per day and the number of years smoked. People who smoke have about 20 times the risk of lung cancer compared to those who do not smoke.
Being exposed to secondhand tobacco smoke is also a risk factor for lung cancer. Secondhand smoke is the smoke that comes from a burning cigarette or other tobacco product, or that is exhaled by smokers. People who inhale secondhand smoke are exposed to the same cancer -causing agents as smokers, although in smaller amounts. Inhaling secondhand smoke is called involuntary or passive smoking.
Having a family history of lung cancer is a risk factor for lung cancer. People with a relative who has had lung cancer may be twice as likely to have lung cancer as people who do not have a relative who has had lung cancer. Because cigarette smoking tends to run in families and family members are exposed to secondhand smoke, it is hard to know whether the increased risk of lung cancer is from the family history of lung cancer or from being exposed to cigarette smoke.
Being infected with the human immunodeficiency virus (HIV), the cause of acquired immunodeficiency syndrome (AIDS), is linked with a higher risk of lung cancer. People infected with HIV may have more than twice the risk of lung cancer than those who are not infected. Since smoking rates are higher in those infected with HIV than in those not infected, it is not clear whether the increased risk of lung cancer is from HIV infection or from being exposed to cigarette smoke.
Studies show that high levels of radon gas inside homes and other buildings increase the number of new cases of lung cancer and the number of deaths caused by lung cancer. The risk of lung cancer is higher in smokers exposed to radon than in nonsmokers exposed to radon. In people who have never smoked, about 30% of deaths caused by lung cancer have been linked to being exposed to radon.
These substances can cause lung cancer in people who are exposed to them in the workplace and have never smoked. As the level of exposure to these substances increases, the risk of lung cancer also increases. The risk of lung cancer is even higher in people who are exposed and also smoke.
Taking beta carotene supplements (pills) increases the risk of lung cancer, especially in smokers who smoke one or more packs a day. The risk is higher in smokers who have at least one alcoholic drink every day.
Adapted from the National Cancer Institute's Physician Data Query (PDQ(r)) Cancer Information Summaries (http://www.cancer.gov/
Last Reviewed: Mar 23, 2015