Conditions InDepth: Lung CancerEn Español (Spanish Version)
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 two types:
- Non-small cell lung cancer—This type generally grows and spreads more slowly. Non-small cell lung cancer accounts for the majority of the lung cancer cases that are diagnosed each year in the United States.
The most common types of non-small cell lung cancer are squamous cell cancer and adenocarcinoma.
- Small cell lung cancer—This type generally grows more quickly. It is more likely to spread to other parts of the body.
Most cases of
lung cancer are associated with
, such as:
- First- or second-hand cigarette smoke
- Pipe or cigar smoking, chewing tobacco
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.gov/cancertopics/pdq/treatment/non-small-cell-lung/Patient/page1. 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 2014