Lung cancer is a disease in which malignant cells form in the lung tissue.
Lungs are a pair of cone-shaped respiratory organs located in the chest cavity.The lungs deliver oxygen into the body when a person inhales and expel carbon dioxide out of the body when they exhale.Each side of the lung can be subdivided into lobes.The left lung has two lobes, while the right lung is slightly larger and has three lobes.The lungs are covered with a membrane called the pleura.The trachea divides into two bronchi, which lead to the right and left lungs respectively. Bronchioles can sometimes develop lung cancer.The interior of the lungs consists of small tubes and air sacs called fine bronchioles and alveoli, respectively.
An anatomical diagram of the respiratory system lists the trachea, left lung, right lung, lobes, and airways. The diagram also shows the lymph nodes and diaphragm.After oxygen is drawn into the lungs, it enters the circulation through the membrane on the alveoli (see inset).
There are two types of lung cancer: small cell lung cancer and non-small cell lung cancer.
For more information about lung cancer, see the following PDQ summary:
Lung cancer is the leading cause of cancer death in the United States. In China, lung cancer is also the leading cause of cancer death.
Lung cancer is the third most common non-skin cancer in the United States. Lung cancer is the leading cause of cancer death in both men and women. Lung cancer is the number one common cancer in China. Lung cancer is the leading cause of cancer death in both men and women.
Different factors can increase or decrease the risk of developing lung cancer.
Any factor that increases the chance of developing the disease is called a risk factor.Any factor that decreases the chance of developing the disease is called a protective factor.
For information on lung cancer risk factors and protective factors, see the PDQ summary on lung cancer prevention.