Effects of breast cancer treatment on the lungs

Very rarely, radiotherapy to the breast area can affect the lungs. This can cause breathlessness.

Effects on the lungs

Radiotherapy can change the cells that line the lungs and cause a hardening and thickening of the tissue. This is called fibrosis. This can cause problems with breathlessness months or years after treatment. This is called a late effect. However, this is a rare side effect because radiotherapy is carefully planned and ways of giving it have improved.

If you already have a chest problem such as asthma, or if you smoke, the symptoms can be worse.

Some women get inflammation of the lung (radiation pneumonitis) 1 to 3 months after radiotherapy. This causes symptoms such as:

However, the condition usually improves so the symptoms will go away.

You should always talk to your doctor if you develop new symptoms.

Treatment for lung problems

Lifestyle changes

Treatment will depend on your situation. You may need to make some lifestyle changes. For example, it is best to give up smoking and keep to a healthy weight. Your doctor or specialist nurse will give you advice and support about this.


You may be given inhalers that contain drugs to help open up the airways. These are called bronchodilators. Or you may be given steroids. These can be given as tablets or inhalers to reduce inflammation. If you have an infection in the lung, you will be given antibiotics.

Looking after your lungs

Making small changes to your lifestyle can reduce your risk of developing lung problems.

  • Give up smoking

    If you smoke, the most important thing you can do is to stop. Stopping smoking has lots of benefits. It is also important to avoid being exposed to other people’s smoke (passive smoking).

  • Keep to a healthy weight

    Keeping to a healthy weight improves breathing problems.

  • Do some breathing exercises

    You can ask to be referred to a physiotherapist who can teach you deep breathing exercises and give you advice on exercise. This can help you breathe better and improve breathlessness.

The British Lung Foundation also has lots of information and advice.