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Lung Cancer Prevention (PDQ®)

Patient Version
Last Modified: 10/07/2011

Lung Cancer Prevention

Key Points for This Section


Avoiding risk factors and increasing protective factors may help prevent lung cancer.

Avoiding cancer risk factors such as smoking, being overweight, and lack of exercise may help prevent certain cancers. Increasing protective factors such as quitting smoking, eating a healthy diet, and exercising may also help prevent some cancers. Talk to your doctor or other health care professional about how you might lower your risk of cancer.

The following are risk factors for lung cancer:

Cigarette, cigar, and pipe smoking

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 have shown that smoking low tar or low nicotine cigarettes does not lower the risk of lung cancer.

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.

Secondhand 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.

Family history

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.

Environmental risk factors

  • Radon exposure: Radon is a radioactive gas that comes from the breakdown of uranium in rocks and soil. It seeps up through the ground, and leaks into the air or water supply. Radon can enter homes through cracks in floors, walls, or the foundation, and levels of radon can build up in the home.

    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.

  • Air pollution: Some studies have shown a link between air pollution and an increased risk of lung cancer.

  • Workplace exposure : Studies have shown a link between being exposed to the following substances and an increased risk of lung cancer:

    These substances can cause lung cancer in people who are exposed to them in the workplace and have never smoked. The risk of lung cancer is higher in people who are exposed and also smoke.

Beta carotene supplements in heavy smokers

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.

It is not clear if the following increases the risk of lung cancer:

HIV infection

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 hard to know whether the increased risk of lung cancer is from the HIV infection or from being exposed to cigarette smoke.

The following are protective factors for lung cancer:

Not smoking

The best way to prevent lung cancer is to not smoke.

Quitting smoking

Smokers can decrease their risk of lung cancer by quitting. In smokers who have been treated for lung cancer, quitting smoking lowers the risk of new lung cancers. Counseling, the use of nicotine replacement products, and antidepressant therapy have helped smokers quit for good.

In a person who has quit smoking, the chance of preventing lung cancer depends on how many years and how much the person smoked and the length of time since quitting. After a person has quit smoking for 10 years, the risk of lung cancer decreases 30% to 50%.

See the following for more information on quitting smoking:

Lower exposure to workplace risk factors

Laws that protect workers from being exposed to cancer-causing substances, such as asbestos, arsenic, nickel, and chromium, may help lower their risk of developing lung cancer. Laws that prevent smoking in the workplace help lower the risk of lung cancer caused by secondhand smoke.

Lower exposure to radon

Lowering radon levels may lower the risk of lung cancer, especially among cigarette smokers. High levels of radon in homes may be reduced by taking steps to prevent radon leakage, such as sealing basements.

It is not clear if the following decrease the risk of lung cancer:

Diet

Some studies show that people who eat high amounts of fruits or vegetables have a lower risk of lung cancer than those who eat low amounts. However, since smokers tend to have less healthy diets than nonsmokers, it is hard to know whether the decreased risk is from having a healthy diet or from not smoking.

Physical activity

Some studies show that people who are physically active have a lower risk of lung cancer than people who are not. However, since smokers tend to have different levels of physical activity than nonsmokers, it is hard to know if physical activity affects the risk of lung cancer.

The following do not decrease the risk of lung cancer:

Beta carotene supplements in nonsmokers

Studies of nonsmokers show that taking beta carotene supplements does not lower their risk of lung cancer.

Vitamin E supplements

Studies show that taking vitamin E supplements does not affect the risk of lung cancer.

Cancer prevention clinical trials are used to study ways to prevent cancer.

Cancer prevention clinical trials are used to study ways to lower the risk of developing certain types of cancer. Some cancer prevention trials are conducted with healthy people who have not had cancer but who have an increased risk for cancer. Other prevention trials are conducted with people who have had cancer and are trying to prevent another cancer of the same type or to lower their chance of developing a new type of cancer. Other trials are done with healthy volunteers who are not known to have any risk factors for cancer.

The purpose of some cancer prevention clinical trials is to find out whether actions people take can prevent cancer. These may include eating fruits and vegetables, exercising, quitting smoking, or taking certain medicines, vitamins, minerals, or food supplements.

New ways to prevent lung cancer are being studied in clinical trials.

Clinical trials are taking place in many parts of the country. Information about clinical trials can be found in the Clinical Trials section of the NCI Web site 3. Check NCI's PDQ Cancer Clinical Trials Registry for prevention trials for non-small cell lung cancer 4 and small cell lung cancer 5 that are now accepting patients. These include trials for quitting smoking.



Glossary Terms

acquired immunodeficiency syndrome (uh-KWY-erd IH-myoo-noh-dih-FIH-shun-see SIN-drome)
A disease caused by human immunodeficiency virus (HIV). People with acquired immunodeficiency syndrome are at an increased risk for developing certain cancers and for infections that usually occur only in individuals with a weak immune system. Also called AIDS.
alcohol (AL-kuh-hol)
A chemical substance found in beer, wine, and liquor, and some medicines, mouthwashes, household products, and essential oils (scented liquid taken from plants). Alcohol contains a carbon atom attached to a hydroxyl group (a molecule made of an oxygen atom and a hydrogen atom).
antidepressant (AN-tee-dee-PREH-sunt)
A drug used to treat depression.
arsenic (ARS-nik)
A poisonous chemical used to kill weeds and pests. Also used in cancer therapy.
asbestos (as-BES-tus)
A group of minerals that take the form of tiny fibers. Asbestos has been used as insulation against heat and fire in buildings. Loose asbestos fibers breathed into the lungs can cause several serious diseases, including lung cancer and malignant mesothelioma (cancer found in the lining of the lungs, chest, or abdomen). Asbestos that is swallowed may cause cancer of the gastrointestinal tract.
beta carotene (BAY-tuh KAYR-uh-teen)
A substance found in yellow and orange fruits and vegetables and in dark green, leafy vegetables. The body can make vitamin A from beta carotene. Beta carotene is being studied in the prevention of some types of cancer. It is a type of antioxidant.
cancer (KAN-ser)
A term for diseases in which abnormal cells divide without control and can invade nearby tissues. Cancer cells can also spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is a cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is a cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is a cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord. Also called malignancy.
clinical trial (KLIH-nih-kul TRY-ul)
A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called clinical study.
counseling (KOWN-suh-ling)
The process by which a professional counselor helps a person cope with mental or emotional distress, and understand and solve personal problems.
diet (DY-et)
The things a person eats and drinks.
family history (FA-mih-lee HIH-stuh-ree)
A record of the relationships among family members along with their medical histories. This includes current and past illnesses. A family history may show a pattern of certain diseases in a family. Also called family medical history.
human immunodeficiency virus (HYOO-mun IH-myoo-noh-dih-FIH-shun-see VY-rus)
The cause of acquired immunodeficiency syndrome (AIDS). Also called HIV.
infection (in-FEK-shun)
Invasion and multiplication of germs in the body. Infections can occur in any part of the body and can spread throughout the body. The germs may be bacteria, viruses, yeast, or fungi. They can cause a fever and other problems, depending on where the infection occurs. When the body’s natural defense system is strong, it can often fight the germs and prevent infection. Some cancer treatments can weaken the natural defense system.
inhalation (IN-huh-LAY-shun)
In medicine, refers to the act of taking a substance into the body by breathing.
involuntary (in-VAH-lun-TAYR-ee)
An action that is not made by choice. In the body, involuntary actions (such as blushing) occur automatically, and cannot be controlled by choice.
lung cancer (lung KAN-ser)
Cancer that forms in tissues of the lung, usually in the cells lining air passages. The two main types are small cell lung cancer and non-small cell lung cancer. These types are diagnosed based on how the cells look under a microscope.
medicine (MEH-dih-sin)
Refers to the practices and procedures used for the prevention, treatment, or relief of symptoms of a diseases or abnormal conditions. This term may also refer to a legal drug used for the same purpose.
mineral (MIH-neh-rul)
In medicine, a mineral is a nutrient that is needed in small amounts to keep the body healthy. Mineral nutrients include the elements calcium, magnesium, and iron.
nicotine (NIH-kuh-TEEN)
An addictive, poisonous chemical found in tobacco. It can also be made in the laboratory. When it enters the body, nicotine causes an increased heart rate and use of oxygen by the heart, and a sense of well-being and relaxation. It is also used as an insecticide.
overweight (OH-ver-WAYT)
Being too heavy for one’s height. Excess body weight can come from fat, muscle, bone, and/or water retention. Being overweight does not always mean being obese.
PDQ
PDQ is an online database developed and maintained by the National Cancer Institute. Designed to make the most current, credible, and accurate cancer information available to health professionals and the public, PDQ contains peer-reviewed summaries on cancer treatment, screening, prevention, genetics, complementary and alternative medicine, and supportive care; a registry of cancer clinical trials from around the world; and directories of physicians, professionals who provide genetics services, and organizations that provide cancer care. Most of this information, and more specific information about PDQ, can be found on the NCI's Web site at http://www.cancer.gov/cancertopics/pdq. Also called Physician Data Query.
prevention (pree-VEN-shun)
In medicine, action taken to decrease the chance of getting a disease or condition. For example, cancer prevention includes avoiding risk factors (such as smoking, obesity, lack of exercise, and radiation exposure) and increasing protective factors (such as getting regular physical activity, staying at a healthy weight, and having a healthy diet).
protective factor (proh-TEK-tiv FAK-ter)
Something that may decrease the chance of getting a certain disease. Some examples of protective factors for cancer are getting regular physical activity, staying at a healthy weight, and having a healthy diet.
radioactive (RAY-dee-oh-AK-tiv)
Giving off radiation.
radon (RAY-don)
A radioactive gas that is released by uranium, a substance found in soil and rock. Breathing in too much radon can damage lung cells and may lead to lung cancer.
risk factor (... FAK-ter)
Something that increases the chance of developing a disease. Some examples of risk factors for cancer are age, a family history of certain cancers, use of tobacco products, being exposed to radiation or certain chemicals, infection with certain viruses or bacteria, and certain genetic changes.
secondhand smoke (SEH-kund-hand ...)
Smoke that comes from the burning of a tobacco product and smoke that is exhaled by smokers. Inhaling secondhand smoke is called involuntary or passive smoking. Also called environmental tobacco smoke and ETS.
supplemental nutrition (SUH-pleh-MEN-tul noo-TRIH-shun)
A substance or product that is added to a person’s diet to make sure they get all the nutrients they need. It may include vitamins, minerals, protein, or fat, and may be given by mouth, by tube feeding, or into a vein.
supplementation (SUH-pleh-MEN-TAY-shun)
Adding nutrients to the diet.
therapy (THAYR-uh-pee)
Treatment.
tobacco (tuh-BA-koh)
A plant with leaves that have high levels of the addictive chemical nicotine. The leaves may be smoked (in cigarettes, cigars, and pipes), applied to the gums (as dipping and chewing tobacco), or inhaled (as snuff). Tobacco leaves also contain many cancer-causing chemicals, and tobacco use and exposure to secondhand tobacco smoke have been linked to many types of cancer and other diseases. The scientific name is Nicotiana tabacum.
vitamin (VY-tuh-min)
A nutrient that the body needs in small amounts to function and stay healthy. Sources of vitamins are plant and animal food products and dietary supplements. Some vitamins are made in the human body from food products. Vitamins are either fat-soluble (can dissolve in fats and oils) or water-soluble (can dissolve in water). Excess fat-soluble vitamins are stored in the body’s fatty tissue, but excess water-soluble vitamins are removed in the urine. Examples are vitamin A, vitamin C, and vitamin E.
vitamin E (VY-tuh-min ...)
A nutrient that the body needs in small amounts to stay healthy and work the way it should. It is fat-soluble (can dissolve in fats and oils) and is found in seeds, nuts, leafy green vegetables, and vegetable oils. Vitamin E boosts the immune system and helps keep blood clots from forming. It also helps prevent cell damage caused by free radicals (highly reactive chemicals). Vitamin E is being studied in the prevention and treatment of some types of cancer. It is a type of antioxidant. Also called alpha-tocopherol.

Table of Links

1http://www.cancer.gov/cancertopics/smoking
2http://www.cancer.gov/cancertopics/pdq/prevention/control-of-tobacco-use/Patient
3http://cancer.gov/clinicaltrials
4http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?diagnosis=40862&tt=4&a
mp;format=1&cn=1
5http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?diagnosis=40962&tt=4&a
mp;format=1&cn=1