Types of lung cancer

There are two main types of primary lung cancer. They behave in different ways and respond to treatment differently. They are:

Non-small cell lung cancer

There are three main types:

  • Adenocarcinoma is the most common type of lung cancer. It develops from mucus-producing cells that line the airways.
  • Squamous cell carcinoma develops in the cells that line the airways. It is usually caused by smoking.
  • Large cell carcinoma (sometimes called undifferentiated carcinoma) is named because of how the cancer cells look when examined under a microscope.

Small cell lung cancer

Small cell lung cancer (SCLC) also gets its name from how the cancer cells look when examined under a microscope. It’s usually caused by smoking, and very rarely develops in someone who has never smoked. SCLC usually grows quickly and can spread quickly.


This is a cancer of the covering of the lungs (the pleura) and is less common. We have separate information about mesothelioma.

Rarer types of lung cancer

Some people get other rarer types of lung cancer. Carcinoid tumours are rare cancers that sometimes develop in the lungs.

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The lungs

When we breathe in, the lungs take oxygen into the bloodstream and circulate it all around the body.

Why do cancers come back?

Sometimes, tiny cancer cells are left behind after cancer treatment. These can divide to form a new tumour.

Cancer and cell types

Cancers are grouped into types. Types of cancer often behave and respond to treatments in different ways.

How it is treated

There are five main types of cancer treatment. You may receive one, or a combination of treatments, depending on your cancer type.

What is cancer?

There are more than 200 different kinds of cancer, each with its own name and treatment.