Lung Cancer

Overview

According to the American Cancer Society, in 2025, an estimated 226,650 new cases of lung cancer will be diagnosed in the U.S. and 124,730 people will die from the disease. Cigarette smoking is the most common cause of lung cancer. However, exposure to asbestos, radon, environmental factors and secondhand smoke can cause lung cancer as well. Genetic factors can also affect risk for lung cancer.

The two main types of lung cancer: non-small cell lung cancer and small cell lung cancer refer to how a cancer looks under the microscope. Non-small cell lung cancer is the most common type of lung cancer.

There are different types of non-small cell lung cancer, including:

• Adenocarcinoma – a cancer that forms in the outer parts of the lung.
• Squamous cell carcinoma – a cancer that forms from a cell lining the airway.
• Large cell carcinoma – a kind of non-small cell lung cancer, but the cell it starts from may not be known.

Small cell lung cancer is less common and accounts for the remainder of cases. Although the cells are small, they multiply quickly and can form large tumors that may spread throughout the body. Small cell lung cancer is almost always due to smoking.