some causes of cancer
Different types of cancer have different causes and are likely to depend on many factors. Some cancers are more common than others, and chances for survival vary among different types. Most cancers do not have known causes from a chemical, environmental, genetic, immunologic, or viral origin. Cancers also can arise spontaneously from causes that are thus far unexplained.
The causes of cancer are very complex, involving both the cell and factors in the environment. Much progress has been made in identifying possible causes of cancer, including:
Tobacco. The most common carcinogens in our society are those present in cigarette smoke.
Tobacco smoke is known to contain at least 60 carcinogens and 6 developmental toxicants. In
addition to being responsible for 80 to 90 percent of lung cancers, cigarette smoking is also
associated with cancers of the mouth, pharynx, larynx, esophagus, pancreas, kidney, and bladder.
Avoiding tobacco products is one way to decrease a person’s risk of cancer.
Chemicals and other substances. Being exposed to substances such as certain chemicals, metals, or pesticides can increase the risk of cancer. Any chemical that is known to cause cancer is called a carcinogen. Asbestos, nickel, cadmium, uranium, radon, vinyl chloride, benzidene, and benzene are examples of well-known carcinogens. These may act alone or along with another carcinogen, such as cigarette smoke, to increase the risk of cancer. For example, inhaling asbestos fibers increases the risk of lung diseases, including cancer, and the cancer risk is especially high for asbestos workers who smoke.
Heredity. Certain types of cancer occur more frequently in some families than in
others, indicating some inherited predisposition to the development of cancer. Even
in these cases, however, environment plays a part in the development of cancer.
Ionizing radiation. Certain types of radiation, such as x-rays, rays from radioactive substances, and
ultraviolet rays from exposure to the sun, can produce damage to the DNA of cells,
which might lead to cancer.
Different types of cancer have different causes and are likely to depend on many factors. Some cancers are more common than others, and chances for survival vary among different types. Most cancers do not have known causes from a chemical, environmental, genetic, immunologic, or viral origin. Cancers also can arise spontaneously from causes that are thus far unexplained.
Tobacco. The most common carcinogens in our society are those present in cigarette smoke.
Tobacco smoke is known to contain at least 60 carcinogens and 6 developmental toxicants. In
addition to being responsible for 80 to 90 percent of lung cancers, cigarette smoking is also
associated with cancers of the mouth, pharynx, larynx, esophagus, pancreas, kidney, and bladder.
Avoiding tobacco products is one way to decrease a person’s risk of cancer.
Chemicals and other substances. Being exposed to substances such as certain chemicals, metals, or pesticides can increase the risk of cancer. Any chemical that is known to cause cancer is called a carcinogen. Asbestos, nickel, cadmium, uranium, radon, vinyl chloride, benzidene, and benzene are examples of well-known carcinogens. These may act alone or along with another carcinogen, such as cigarette smoke, to increase the risk of cancer. For example, inhaling asbestos fibers increases the risk of lung diseases, including cancer, and the cancer risk is especially high for asbestos workers who smoke.
Heredity. Certain types of cancer occur more frequently in some families than in
others, indicating some inherited predisposition to the development of cancer. Even
in these cases, however, environment plays a part in the development of cancer.
Ionizing radiation. Certain types of radiation, such as x-rays, rays from radioactive substances, and
ultraviolet rays from exposure to the sun, can produce damage to the DNA of cells,
which might lead to cancer.
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