What is lung cancer?

The lungs are the parts of the body that we use to breathe. Lung cancer is the third most common cancer in the UK. About 46,400 people are diagnosed with it each year.

There are two main types of primary lung cancer. These are:

Sometimes cancer spreads to the lungs from somewhere else in the body. This is called lung metastases or secondary lung cancer.

We also have information about cancer that affects the lining that covers the lungs (the pleura). This is called pleural mesothelioma.

Some people may get another type of cancer that starts in the lung. For example, a neuroendocrine tumour is a rare cancer type that sometimes starts in the lungs. We have more information about neuroendocrine tumours.


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Symptoms of lung cancer

If you are worried about signs of lung cancer, we have more information about the signs and symptoms. If you have any lung cancer symptoms or notice anything that is unusual for you, see your GP straightaway.

Causes of lung cancer

Smoking cigarettes is the main cause of lung cancer. People who do not smoke can still develop lung cancer, but their risk is much lower.

If someone stops smoking, their risk of developing lung cancer gets lower over time. After about 15 years it is almost the same as a non-smoker.

Lung cancer is also more common in older people. We have more information about the causes and risk factors of lung cancer.

Diagnosis of lung cancer

People who have symptoms usually begin by seeing their GP. If the GP thinks your symptoms could be caused by lung cancer, they will arrange either:

If these tests show anything abnormal, your GP will refer you to see a chest specialist within 2 weeks. Sometimes they will do this before getting the result of the chest x-ray.

At the hospital the specialist will explain any other tests you need before a diagnosis of lung cancer can be made.

Other tests you may have at the hospital include:

PET-CT scan

A PET-CT scan combines 2 types of scan. A CT takes a series of x-rays to build up a 3D picture. A PET measures the activity of cells in the body.


The doctor or nurse collects samples (biopsies) of cells or tissue from the lung or nearby lymph nodes. The samples are checked under a microscope for cancer cells. This test can help diagnose lung cancer and show whether it is SCLC or NSCLC. There are different ways of collecting biopsies, including: 

Waiting for tests results can be a difficult time, we have more information that can help.

Further tests for lung cancer

If tests show you have lung cancer, your specialist will arrange further tests. These can help find out more about your general health and the stage of the cancer:


A mediastinoscopy is when the doctor inserts a long, thin tube into your chest through a small cut at the base of your neck. You have this under a general anaesthetic. They examine the middle of the chest and lymph nodes and take samples of tissue (biopsies).


A thoracoscopy is when the doctor inserts a thin tube through cuts in your chest. You have this under a general anaesthetic. They take samples (biopsies) of the lining of the lungs (the pleura) and can remove fluid that may have collected there.

MRI scan

An MRI scan uses magnetism to build up a detailed picture of areas of your body.

Ultrasound scan

An ultrasound scan uses sound-waves to look at parts of the body, such as the liver, to see if the cancer has spread.

Breathing and heart tests

Breathing and heart tests are used to check how well your lungs and heart are working. You may have this if your treatment plan involves surgery or radiotherapy.


Stages of lung cancer

The stage of a cancer describes its size and if it has spread. The stage will be based on your test results. We have more information about lung cancer stages.

You and your doctors can then talk about the best treatment choices for you.

Treatment for lung cancer

Treatment for lung cancer may include surgery, radiotherapy, chemotherapy, targeted therapy, immunotherapy drugs or a combination of these.

We have more information about lung cancer treatments. Your treatment plan will depend on the stage and type of lung cancer and your general health.

A team of specialists will meet to discuss the best possible treatment for you. This is called a multidisciplinary team (MDT).

Your doctor will explain the different treatments and their side effects. They will also talk to you about the things you should consider when making treatment decisions.

After lung cancer treatment

You have regular follow-up appointments after treatment. This will include regular CT scans or chest x-rays

You may get anxious before the appointments. This is natural. It may help to get support from family, friends or a support organisation.

Macmillan is also here to support you. If you would like to talk, you can:

Even if you already have a healthy lifestyle, you may choose to make some positive lifestyle changes after treatment.

Making small changes such as eating well and keeping active can improve your health and well-being and help your body recover.

Reviewed: 30 September 2018
Reviewed: 30/09/2018
Next review: 30 September 2021
Next review: 30/09/2021