Significance of lung cancer
Lung cancer prevention

The lungs are part of the respiratory system. Their function is to supply oxygen to the blood while removing carbon dioxide.

Lung cancer may spread to the lymph nodes or other tissues in the chest (including the other lung). In many cases, lung cancer may also spread to other organs of the body, such as the bones, brain, or liver.

Lung cancer is the leading cause of cancer deaths in U.S. men and women.

Lung cancer can often be associated with known risk factors for the disease. Many risk factors can be changed, but not all can be avoided.

Tobacco: Studies show that smoking tobacco products in any form is the major cause of lung cancer. People who stop smoking and never start again lower their risk of developing lung cancer or of having lung cancer recur (come back). Many products, such as nicotine gum, nicotine sprays, nicotine inhalers, nicotine patches, or nicotine lozenges, as well as antidepressant drugs, may be helpful to people trying to quit smoking. Never smoking lowers the risk of dying from lung cancer.

Second-hand tobacco smoke also causes lung cancer. This is smoke that comes from a burning cigarette or other tobacco product, or smoke that is exhaled by smokers. People who inhale second-hand smoke are exposed to the same cancer-causing agents as smokers, although in weaker amounts. Inhaling second-hand smoke is called involuntary or passive smoking.

Environmental Causes: There are other causes of lung cancer in the environment, but their effect on lung cancer rates is small compared to the effect of cigarette smoking.

Cancer-causing agents that may be found indoors, especially in the workplace, include asbestos, radon, arsenic, chromium, nickel, tar, and soot. These substances can cause lung cancer in people who have never smoked, and combine with cigarette smoke to further increase lung cancer risk in smokers. Many countries are working to control these cancer-causing agents in the workplace.

Air pollution may also increase the risk of lung cancer. Studies show that lung cancer rates are higher in cities with higher levels of air pollution.

Beta Carotene: Studies show that heavy smokers who avoid taking beta carotene supplements may avoid further increasing their risk of lung cancer compared with smokers who do take beta carotene.

Diet and Physical Activity: Studies show that a diet rich in fruit, and possibly vegetables, may help lower the risk of lung cancer, while heavy alcohol drinking may increase the risk of lung cancer. In addition, studies show that people who are physically active may have a lower risk of lung cancer than those who are not, even after taking cigarette smoking into account.

Chemoprevention: Chemoprevention is the use of specific natural or man-made drugs to reverse, suppress, or prevent cancer growth. Chemoprevention is an area of active clinical research. It has not yet become standard therapy.

Glossary Terms

A drug used to treat depression.

A poisonous chemical used to kill weeds and pests. Also used in cancer therapy.

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.

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.

A tissue with red blood cells, white blood cells, platelets, and other substances suspended in fluid called plasma. Blood takes oxygen and nutrients to the tissues, and carries away wastes.

The use of drugs, vitamins, or other agents to try to reduce the risk of, or delay the development or recurrence of, cancer.

Having to do with the examination and treatment of patients.

The things a person eats and drinks.

Any substance, other than food, that is used to prevent, diagnose, treat or relieve symptoms of a disease or abnormal condition. Also refers to a substance that alters mood or body function, or that can be habit-forming or addictive, especially a narcotic.

Smoke that comes from the burning of a tobacco product and smoke that is exhaled by smokers. Inhaling environmental tobacco smoke is called involuntary or passive smoking. Also called ETS and secondhand smoke.

In medicine, refers to the act of taking a substance into the body by breathing.

A large organ located in the upper abdomen. The liver cleanses the blood and aids in digestion by secreting bile.

One of a pair of organs in the chest that supplies the body with oxygen, and removes carbon dioxide from the body.

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.

A rounded mass of lymphatic tissue that is surrounded by a capsule of connective tissue. Lymph nodes filter lymph (lymphatic fluid), and they store lymphocytes (white blood cells). They are located along lymphatic vessels. Also called lymph gland.

A chewing gum that contains a small dose of nicotine, which enters the blood by being absorbed through the lining of the mouth. This helps stop nicotine cravings and relieves symptoms that occur when a person is trying to quit smoking. A prescription is not needed for nicotine gum.

A device used to inhale (breathe in) small doses of nicotine through the mouth. The nicotine is absorbed through the lining of the mouth and goes into the blood. This helps stop nicotine cravings, and relieves symptoms that occur when a person is trying to quit smoking. A prescription is needed for nicotine inhalers.

A hard candy-like tablet that contains a small dose of nicotine. The nicotine is absorbed through the lining of the mouth and goes into the blood. This helps stop nicotine cravings, and relieves symptoms that occur when a person is trying to quit smoking. A prescription is not needed for nicotine lozenges.

A nose spray that contains a small dose of nicotine, which enters the blood by being absorbed through the lining of the nose. This helps stop nicotine cravings and relieves symptoms that occur when a person is trying to quit smoking. A prescription is needed for nicotine nasal spray.

A patch that sticks on the skin and contains a small dose of nicotine, which enters the blood by being absorbed through the skin. This helps stop nicotine cravings and relieves symptoms that occur when a person is trying to quit smoking. A prescription is not needed for nicotine patches.

A part of the body that performs a specific function. For example, the heart is an organ.

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.

To come back or to return.

The organs that are involved in breathing. These include the nose, throat, larynx, trachea, bronchi, and lungs. Also called respiratory tract.

Something that may increase the chance of developing a disease. Some examples of risk factors for cancer include age, a family history of certain cancers, use of tobacco products, certain eating habits, obesity, lack of exercise, exposure to radiation or other cancer-causing agents, and certain genetic changes.

In medicine, treatment that experts agree is appropriate, accepted, and widely used. Health care providers are obligated to provide patients with standard therapy. Also called best practice and standard of care.

Adding nutrients to the diet.

A group or layer of cells that work together to perform a specific function.

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.