Definition of Lung cancer - non-small cell:

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. It usually grows and spreads more slowly than small cell lung cancer.

There are three forms of NSCLC:

• Adenocarcinomas are often found in an outer area of the lung.
• Squamous cell carcinomas are usually found in the center of the lung by an air tube (bronchus).
• Large cell carcinomas can occur in any part of the lung. They tend to grow and spread faster than the other two types.

Causes, incidence, and risk factors:

Smoking causes most cases of lung cancer. Being around the smoke from others (secondhand smoke) also raises your risk for lung cancer. However, people who do not smoke and have never smoked have become sick with lung cancer.

A review of decades of research has recently shown that smoking marijuana may help cancer cells grow, but there is no direct link between the drug and lung cancer.

High levels of air pollution, working with or near cancer-causing chemicals or materials (such as asbestos), and drinking water containing high levels of arsenic can increase your risk for lung cancer. Radiation therapy to the lungs can also increase the risk.