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Non-Small-Cell Lung Cancer

Non–Small-Cell Lung Cancer Overview

Cancers are diseases in which normal cells transform so that they grow and multiply without normal controls. In many types of cancer, this results in the growth of one or more large masses, or tumors, of these transformed cells. This can happen in almost any part of the body. When it happens in the lungs, the disease is called lung cancer.

Lung cancer is one of the most common types of cancer; this is because the lungs are exposed to the external environment more than most other organs are. In many cases, cancer-causing substances (carcinogens) in the air are inhaled and cause cell damage that later becomes cancer. The most common cause of lung cancer, by far, is smoking.

Two main types of lung cancer exist: small cell lung cancer and non-small-cell lung cancer. Non-small-cell lung cancer is a catchall term for all lung cancers that are not small-cell type. They are grouped together because the treatment is the same for all non-small-cell types. Together, non-small-cell lung cancers, or NSCLCs, make up about 75% of all lung cancers. Each type is named for the types of cells that were transformed to become cancer. The following are the 3 most common types of NSCLC in the United States:

Adenocarcinoma/bronchoalveolar - 35-40%

Squamous cell carcinoma - 25-30%

Large-cell carcinoma - 10-15%

Like all cancers, lung cancer is most easily and successfully treated if it is caught early. An early-stage cancer is less likely to have grown to a large size or to have spread to other parts of the body (metastasized). Large or metastasized cancers are much more difficult to treat.