Lung cancer is a disease in which cancer cells grow in the lungs.
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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 2 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. Lung cancer is the leading cause of death from cancer in the United States.
General information about non-small cell lung cancer. National Cancer Institute website. Available at: http://www.cancer.gov/types/lung/patient/non-small-cell-lung-treatment-pdq. Accessed September 28, 2012.
Lung cancer (non-small cell) overview. American Cancer Society website. Available at: http://www.cancer.org/cancer/lungcancer-non-smallcell/overviewguide/lung-cancer-non-small-cell-overview-treating-general-info. Updated February 23, 2012. Accessed September 28, 2012.
Last reviewed September 2015 by Mohei Abouzied, MD Last Updated: 9/17/2014