Lung cancer is a disease in which cancer cells grow in the lungs.
Lung cancer occurs when cells in the lung divide without control or order. Normally, cells divide in a regulated manner. If cells keep dividing uncontrollably when new cells are not needed, a mass of tissue forms, called a growth or tumor. The term cancer refers to malignant tumors, which can invade nearby tissues and can spread to other parts of the body. A benign tumor does not invade or spread.
Lung cancers that start in the lungs are divided into two types:
Most cases of lung cancer are associated with tobacco use, such as:
While most cases of lung cancer are due to smoking, a percentage of people with lung cancer have never smoked, nor have they been exposed to secondhand smoke.
General information about non-small cell lung cancer. National Cancer Institute website. Available at: http://www.cancer.... . Accessed September 28, 2012.
Lung cancer (non-small cell) overview. American Cancer Society website. Available at: http://www.cancer.... . Updated February 23, 2012. Accessed September 28, 2012.
Last reviewed October 2012 by Igor Puzanov, MD
Last Updated: 10/11/2012