Radiotherapy for secondary breast cancer

Radiotherapy can be used to treat secondary breast cancer. This is called palliative radiotherapy. It is used to relieve pain and other symptoms when breast cancer has spread to the bones, skin or brain.

What is radiotherapy?

Radiotherapy uses high-energy rays called radiation to treat cancer. It destroys cancer cells in the area where the radiotherapy is given, while doing as little harm as possible to normal cells.

Radiotherapy can be used to treat secondary breast cancer. This is called palliative radiotherapy. You may have radiotherapy to relieve pain from secondary breast cancer in the bone. Radiotherapy can also be used to shrink secondary cancer in the brain or lymph nodes. It can also be used when breast cancer has spread to the skin.

Having radiotherapy for secondary breast cancer

You often have between 1 and 5 sessions. Some people have more. Each treatment session will only take a few minutes.

Radiotherapy is not painful, but during treatment you have to lie in 1 position. Staying still in this position may be uncomfortable. Your cancer doctor may suggest taking a painkiller half an hour (30 minutes) before having radiotherapy to help.

Side effects of radiotherapy for secondary breast cancer

You may have some mild side effects from radiotherapy. The main side effect is tiredness. This sometimes lasts for a few weeks after treatment finishes. Other side effects depend on the area of the body being treated and how much radiotherapy you have.

Your cancer doctor, specialist nurse or radiographer will tell you what to expect. They will give you advice on what you can do to manage side effects. If you have any new side effects or if side effects get worse, tell them straight away. 

Some side effects can be worse after treatment ends – for example, skin reactions. It may take about 1 week before they stop or begin to slowly improve.

Radiotherapy to the bones

Radiotherapy to the bones can:

  • shrink a secondary cancer in the bone
  • strengthen the bone
  • reduce pain.

It may take 3 to 4 weeks before treatment works, so you will need to keep taking painkillers during this time. Some people find the pain feels worse for a few days before it starts to improve. Your cancer doctor may prescribe steroid tablets to help with this.

Feeling very tired is a common side effect. This should slowly improve a few weeks after treatment finishes. Try to pace yourself and get as much rest as you need. It helps to balance this with some gentle exercise, such as short walks, if possible.

You may feel sick if the area treated is close to your tummy (abdomen) – for example, the ribs or spine. Your cancer doctor can prescribe anti-sickness drugs to help with this.

Radiotherapy to the pelvis can sometimes cause diarrhoea. Your cancer doctor can prescribe anti-diarrhoea drugs to control this.

Booklets and resources

Spinal cord compression

Doctors can also give a short course of radiotherapy to the spine. This is used when a tumour is close to, or pressing on, the spinal cord and nerves. This is called spinal cord compression.

Spinal cord compression can cause different symptoms depending on the area that is affected. These include:

  • unexplained pain in your back, neck, or down your arm or legs
  • pain that may feel like a tight band around your body
  • numbness or pins and needles in your arms, legs, toes, fingers, chest, back, tummy or buttocks
  • weakness in your arms or legs
  • unsteadiness or difficulty walking
  • problems controlling your bladder or bowel.

Spinal cord compression is not common but needs to be treated quickly. This is to prevent permanent damage to the nerves. Tell your doctor or nurse straight away if you notice any of these symptoms.

Radiotherapy to the brain

Radiotherapy to the brain can help shrink a secondary cancer in the brain and improve the symptoms.

For some people, a type of radiotherapy called stereotactic radiosurgery is suitable. It is not suitable for everyone. It uses high doses of radiation which are targeted directly at the tumour. This causes less damage to surrounding tissue.

Radiotherapy to the brain can cause some hair loss, but this is usually temporary. Your hair should start to grow back a few months after treatment ends, but it can sometimes stay patchy. This is caused by different doses of radiotherapy being used on different parts of the brain. The skin on your scalp may also become dry and feel irritated. Your specialist nurse or radiographer will give you advice on looking after the skin.

You may feel very tired or drowsy for a few weeks. Tiredness can continue for weeks or months after treatment. Get plenty of rest, but try to do some gentle exercise such as   short walks, if you can. This can help give you more energy.

Radiotherapy to the brain may make you feel sick or be sick. Your cancer doctor can prescribe anti-sickness tablets or steroids to control this. We have more information about stereotactic radiosurgery for brain tumours.

About our information

  • References

    Below is a sample of the sources used in our secondary breast cancer information. If you would like more information about the sources we use, please contact us at

    National Institute for Health and Clinical Excellence (NICE). Advanced breast cancer: diagnosis and treatment. Clinical Guideline [CG81]. Updated 2017. Available from: (accessed November 2021).

    BMJ best practice. Metastatic breast cancer. Available from: (accessed November 2021).

  • 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 Dr Rebecca Roylance, Consultant Medical Oncologist and Professor Mike Dixon, Professor of Surgery and Consultant Breast Surgeon.

    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 July 2023
Next review: 01 July 2026
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.