In 2009, an estimated 219,440 new lung cancers were diagnosed in the United States. Although lung cancers can occur at any age, studies show that they are most commonly diagnosed in persons age 65 or older.
Factors that may increase risk:
Smoking tobacco — research has found that most cases of lung cancer are caused by exposure to tobacco smoke. Although the risk of developing lung cancer is greater for the smoker, secondhand smoke can cause lung cancer in nonsmokers.
Radon exposure — people who work in mines may be exposed to radon, a radioactive gas that forms in soil and rocks, which you cannot see, smell, or taste. It may also be found in houses. Research has shown that radon exposure can damage lung cells, and may increase the risk of developing lung cancer.
Asbestos exposure — a chemical substance found in the environment and, at one time, used in the construction and chemical industries. Exposure to asbestos has been shown to increase a person’s risk of developing certain lung cancers and mesothelioma. Many cases are thought to be caused by inhaled asbestos exposure in the environment. However, the lifetime risk of developing the disease among asbestos workers is thought to be as high as 10 percent.
Many studies have shown that air pollution may also increase the risk of lung cancer.
Additionally, people who have had a lung cancer have an increased risk of developing a second lung cancer. Family history may also increase your risk. Lung cancer may also appear in people with few or no risk factors.
Lung cancers can be classified as either small cell or non-small cell, depending on the type of cells affected.
Cancers originating elsewhere in the body often metastasize (spread) to the lung. These cancers are not considered to be lung cancers, since the cancer formed elsewhere in the body.
At the time of diagnosis, lung cancers are given a “stage.” The stage indicates how much the cancer has advanced, and where in the body the cancer is located. The stage of the cancer, along with the type of cancer it is, will determine what type of treatment will be the most effective.
Esophageal cancer is a rare cancer that shares some similarities to lung cancer. Many doctors who treat lung cancer also treat cancers of the esophagus. In esophageal cancer, tissues in the esophagus (the tube that carries food and liquid from the mouth to the stomach) become cancerous. Learn more about esophageal cancer.
Mesothelioma is a malignant disease of the pleural and peritoneal cavities, thought to be caused by inhaled asbestos exposure in the environment. Symptoms often include shortness of breath and chest pain. Mesothelioma is not easily treated with conventional therapies. Learn more about mesothelioma.