What is lung cancer?

Clinical oncologist, Neil Bayman, explains what lung cancer is, the main types, risk factors, stages and common treatments available to you.


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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Booklets and resources

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.
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Causes of lung cancer

Smoking tobacco is the cause of most lung cancers and the biggest risk factor. This includes smoking cigarettes, cigars and pipes. 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 risk factors of lung cancer.

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Diagnosis of lung cancer

People may be diagnosed with lung cancer after seeing their GP about their symptoms. If your GP thinks your symptoms could be caused by lung cancer, they will arrange tests to help make a diagnosis. These can include:

If these tests show anything abnormal, your GP will refer you to 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. These may 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.

  • Biopsy

    During a biopsy, a doctor or nurse takes samples of cells or tissue from the abnormal area. They look at the biopsy samples under a microscope to check for cancer cells. You usually have a biopsy to find out for certain if you have lung cancer. 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 may be to help with the staging of lung cancer

You may have the following tests:

  • Mediastinoscopy

    A mediastinoscopy is sometimes done instead of an EBUS or EUS. It lets the doctor look at the area in the middle of your chest (the mediastinum) and nearby lymph nodes. You have it under a general anaesthetic. 

  • Thoracoscopy

    A thoracoscopy lets the doctor look at the lining of the lungs (pleura). It is usually done under a general anaesthetic.

  • MRI scan

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

  • Breathing tests

    If your treatment plan involves having surgery or radiotherapy your doctor will arrange breathing tests (lung-function tests) and exercise tests.

    These help doctors see how well your lungs are working. You may also have tests to check how well your heart is working.

Stages of lung cancer

The stage of a cancer describes its size and position, and if it has spread from where it started. Knowing the stage helps your doctors advise the best treatment for you.

We have more information about the staging of lung cancer.

Treatment for lung cancer

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

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.

We have more information about treatment for lung cancer.

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.

Getting support

Everyone has their own way of dealing with illness and the different emotions they experience. You may find it helpful to talk things over with family and friends or your doctor or nurse.

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

Well-being and recovery

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.

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Get this information in another language or format

We are committed to making our website as accessible as possible, to make sure that everyone can use it.

We have information about lung cancer in over 16 languages, and in other formats including audiobooks, and easy read.

If we don't have what you are looking for, you can ask for information to be translated for free or provided in a format to suit you. Email us at cancerinformationteam@macmillan.org.uk or call us on 0808 808 00 00.

About our information

  • References

    Below is a sample of the sources used in our lung cancer information. If you would like more information about the sources we use, please contact us at  cancerinformationteam@macmillan.org.uk

    National Institute for Health and Care Excellence (NICE). Lung cancer – Diagnosis and management. Clinical guideline 2019.

    Metastatic non-small cell lung cancer: ESMO clinical practice guidelines for diagnosis, treatment and follow-up. 2018.

    European Society for Medical Oncology (ESMO). Early and locally advanced non-small-cell lung cancer (NSCLC): ESMO clinical practice guidelines for diagnosis, treatment and follow-up. 2017.

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editor, Dr David Gilligan, Consultant Clinical Oncologist.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

The language we use

We want everyone affected by cancer to feel our information is written for them.

We want our information to be as clear as possible. To do this, we try to:

  • use plain English
  • explain medical words
  • use short sentences
  • use illustrations to explain text
  • structure the information clearly
  • make sure important points are clear.

We use gender-inclusive language and talk to our readers as ‘you’ so that everyone feels included. Where clinically necessary we use the terms ‘men’ and ‘women’ or ‘male’ and ‘female’. For example, we do so when talking about parts of the body or mentioning statistics or research about who is affected.

You can read more about how we produce our information here.

Date reviewed

Reviewed: 01 November 2020
Next review: 01 November 2023

This content is currently being reviewed. New information will be coming soon.

Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

This means it is easy to use, up-to-date and based on the latest evidence. Learn more about how we produce our information.