Lung Cancer Stages, Prognosis, Causes, and Diagnosis
An estimated 228,000 new lung cancers are diagnosed every year 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.
What is Lung Cancer?
Lung cancer can be classified as either small cell or non-small cell, depending on the type of cells affected.
- Small cell lung cancer forms in the larger airways of the lung, accounts for about 15 percent of the cases of lung cancer, and is strongly associated with smoking tobacco.
- Nonsmall cell lung cancer is a group of similar cancers. These include adenocarcinoma, squamous cell lung carcinoma, and large-cell carcinoma.
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 your diagnosis, your doctor will “stage” your lung cancer. The stage indicates how much your cancer has advanced and where in your body the cancer is located.
The stage of your cancer, along with the type of cancer, will determine what type of treatment will be the most effective.
Factors that may increase your risk for lung cancer include:
- 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 — Asbestos is 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 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.
More about Lung Cancer
Learn more about lung cancer from the National Cancer Institute: