What are the types of lung cancer?

Non-small cell lung cancer (NSCLC)

Most lung cancers are this type. 

There are 4 main types of NSCLC: 

• Adenocarcinoma: This is the most common type of lung cancer and is often found in the mucous glands that line the airways. 
• Squamous cell carcinoma: This type of cancer is found in squamous cells, which are flat cells that line the inside of the airways in your lungs. 
• Large cell carcinoma: This cancer may appear in any part of your lung. The cells are large and round when viewed under the microscope. 
• Not otherwise specified (NOS): This is when the doctors cannot be sure which type of non-small cell lung cancer it is.

Genetic alterations (mutations) in NSCLCs

Some NSCLC cancers have genetic changes (mutations), which are not inherited. When these mutations occur in cells in the lungs, they affect the normal activity of the gene, and lung cancer can develop. Mutations in the EGFR, KRAS, ROS1 and ALK genes can happen in lung cancers – particularly in adenocarcinomas and in patients who have had little or no exposure to smoking.

Small cell lung cancer (SCLC)

About 1 in 7 of all lung cancers is the small cell type. 

Small cell lung cancer begins in cells around the bronchi (airways) called neuroendocrine cells (NETs). SCLC cells appear small and round when looked at under a microscope and tend to grow quickly. 

SCLC is an aggressive cancer with the potential to grow and spread rapidly. It often spread to lymph nodes and other areas such as your bones, brain, adrenal glands and liver.

Mesothelioma

This rare cancer affects the protective linings that cover your lungs. Usually it happens when someone is exposed to a chemical called asbestos.

Read more about mesothelioma.