Non-Small Cell Lung Cancer

Non-small cell lung cancer accounts for at least 80% of lung cancers in the United States. It does not spread as rapidly as small cell lung cancer, but is still frequently diagnosed after a surgical cure is not possible. Smoking is the leading cause of lung cancer, but factors other than smoking are more likely to contribute to this type of lung cancer. There are 3 primary types of non-small cell lung cancer.

Adenocarcinoma

Adenocarcinoma is the most common form of non-small cell lung cancer accounting for up to 50% of cases in the United States. It is usually the type of lung cancer found in non-smokers, and is the most common type seen in women. It starts in the periphery of the lungs and can be present for a long time before it is detected. A less common form of adenocarcinoma is bronchioalveolar carcinoma. This type of lung cancer arises in the small air sacs in the lungs. It responds fairly well to some of the new lung cancer treatments called targeted therapies.

Squamous cell carcinoma (epidermoid carcinoma)

Squamous cell carcinoma used to be more common, but now accounts for roughly 30% of non-small cell lung cancers in the United States. It usually starts in the bronchial tubes, centrally in the lungs, and commonly is found after individuals begin to cough up blood (hemoptysis). It has been speculated that filtered cigarettes have caused the decline in squamous cell lung cancer and that adenocarcinoma is more common now since toxins are inhaled deeper into the lungs.

Large cell carcinoma

Large cell cancers are less common accounting for up to 10% of non-small cell lung cancers in the United States. They occur in the outer edges of the lungs and tend to grow rapidly.

_{Resources:
National Institute of Health. Medline Plus. Lung Cancer. Updated 02/12/08.
College of American Pathologists. Lung Cancer. Lung Adenocarcinoma. July 2006.}