Types of Lung Cancer

Lung cancer is any cancer that starts in lung structures. These structures include the:¹

• Bronchi (air tubes)
• Bronchioles (smaller air tubes)
• Alveoli (air sacs)

Lung cancer types are defined by how cancer cells look under a microscope. Different types of lung cancer vary in how they grow, their risk of spreading to other parts of the body, and possible health outcomes.¹

The 2 main types of lung cancer are non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Other types are less common. Treatment varies depending on several factors, including the type and stage of lung cancer.^1-3

Non-small cell lung cancer (NSCLC)

The most common type of lung cancer is non-small cell lung cancer. NSCLC accounts for 80 to 85 percent of all lung cancers. Some subtypes of NSCLC start in the outer regions of the lungs. Others begin in the central parts of the lung. Treatment and health outcomes for the NSCLC subtypes are often similar.^1,2,4

The main subtypes of NSCLC are:

Adenocarcinoma

Adenocarcinoma is the most common type of NSCLC. It typically starts in an outer area of the lung in cells that make mucus. These are called lung epithelial cells. It happens mostly in people who smoke or used to smoke. It is also the most common type of lung cancer in people who do not smoke.^1,2

Squamous cell carcinoma

Squamous cells line the inside of the airways in the lungs. Squamous cell carcinoma is often linked to smoking history. This type of NSCLC is often found near the main bronchi in the central part of the lungs.^1,2

Large cell carcinoma

Large cell carcinoma often grows and spreads faster than other NSCLC subtypes. This can make it harder to treat. It can appear in any part of the lung.^1,2

Other NSCLC subtypes

A few other subtypes are much less common. These include adenosquamous carcinoma and sarcomatoid carcinoma.¹

Small cell lung cancer (SCLC)

Small cell lung cancer accounts for 10 to 15 percent of all lung cancers. It is almost always associated with a history of smoking. It often begins in the lungs, around or near the bronchi. SCLC typically grows and spreads faster than NSCLC. The cancer has often spread beyond the lungs at the time of diagnosis. Chemotherapy and radiation therapy are common treatments for people with SCLC.^1,2,4

There are 2 subtypes of SCLC:⁴

• Small cell carcinoma (oat cell cancer)
• Combined small cell carcinoma

Lung carcinoid tumor

Lung carcinoid tumors make up less than 5 percent of all lung cancers. They tend to grow slowly. They are made up of neuroendocrine cells. These cells release hormones that regulate different organs. Lung carcinoid tumors are commonly treated with surgery.^1,2

Mesothelioma

Mesothelioma is not a true lung cancer. It is a rare cancer of the chest lining. But it accounts for about 5 percent of all lung cancers. It can develop 30 to 50 years after exposure to asbestos. Most people with mesothelioma worked in places where they were exposed to asbestos. A combination of treatments may be used for people with mesothelioma.⁴

Lung cancer types and treatment

Your type of lung cancer is only one factor that determines the best treatment option. Your overall health, stage of cancer, and preferences also impact your treatment plan. Your doctor can work with you to find the best options.^5-8

Treatments for lung cancer work better at earlier stages. Treatment can be harder once the cancer has spread to other areas of the body. Unfortunately, many people with lung cancer are diagnosed at later stages.^5-8