Types of Lung Cancer

Any cancer that has its origins in the lungs or any of its structures, like the bronchi (air tubes) or alveoli (air sacs), is named lung cancer. There are several different types of lung cancer, notable for their clinical and biologic differences. Different types of lung cancer also have variations in their growth pattern, propensity to spread or metastasize to other parts of the body, prognoses (or projected outcomes), and require different treatment.^1,2

Non-small cell lung cancer (NSCLC)

The most common type of lung cancer is non-small cell lung cancer. NSCLC accounts for 85 percent of all lung cancers. Some NSCLC develop in the periphery (outer regions) of the lungs, and some begin in the central parts of the lung. Within the category of NSCLC are several additional classifications, including:

• Adenocarcinoma
• Squamous cell carcinoma
• Large cell carcinoma
• Other rare NSCLC, such as adenosquamous carcinoma and sarcomatoid carcinoma^1,2

Small cell lung cancer (SCLC)

Small cell lung cancer accounts for 15 percent of all lung cancers. It begins in lungs around or near the bronchi. SCLC is an aggressive, rapidly growing cancer, and it is likely to invade surrounding tissues and metastasize to other areas of the body.^2,3

Lung carcinoid tumor

Lung carcinoid tumors make up less than 5 percent of all lung cancers and tend to be slower growing. Because they are made up of neuroendocrine cells, they are also known as lung neuroendocrine tumors. Neuroendocrine cells are found throughout the body and produce hormones that affect functioning in different organs, however, this does not mean patients have cancer throughout their body.³

Mesothelioma

Although not a true lung cancer, mesothelioma is a cancer that can affect the lining around the lungs. It is most often caused by exposure to asbestos in the workplace.³

Differences in lung cancer types determine treatment

In addition to the stage, or extent, of the cancer, doctors look at the cellular structure of a tumor under the microscope to determine its type. The type of lung cancer helps doctors to recommend appropriate treatment options. Several unique molecular characteristics have been identified that have led to the development of targeted treatments. Targeted treatments have been shown to improve the survival of specific types of cancer in patients with metastatic disease.¹

Lung cancer, like other cancers, is most curable in its earliest stages, before it has spread to other areas of the body. Unfortunately, most lung cancers are diagnosed at later stages.¹