Breast cancer: Understanding late effects of radiotherapy
Late side effects may happen a few months or years after treatment. They might happen once, carry on over the long term or come and go. Sometimes they cannot be cured, but it might be possible to manage them.
You might have late effects not listed here, because everyone is different. They may also be caused by a different part of your cancer treatment. It is not possible to predict if you will get them and when they might happen, which can be difficult to come to terms with. Research and support for late effects of radiotherapy is growing.
Joining a support group can be a positive way to share your experiences, feel less alone, and come to terms with the physical and emotional impact of treatment. Ask your clinical team if you need more support or have any late effects at all.
This page looks at late side effects.
How likely am I to get late side effects?
Before treatment you will discuss and sign a consent form with your clinical oncologist or therapeutic radiographer. They will tell you what to expect, and you can ask questions and discuss any concerns you have about late effects.
You can read different radiotherapy consent forms (HERE) based on the specific area being treated. These consent forms are packed with useful information about early and late side effects.(1)
When you consent to treatment, you are saying you understand that you have a chance of getting late side effects. Your team will use words like Expected, Common, Less Common and Rare.
This table shows what these words mean.
| Wording on the consent form | % chance of side or late effect | How many patients will get this? |
|---|---|---|
| Expected | 50 to 100% | Between half and all patients |
| Common | 10 to 50% | Up to half of all patients |
| Less common | Less than 10% | Fewer than one in ten patients |
| Rare | Less than 1% | Fewer than one in 100 patients |
Possible late side effects
- Skin reactions: Sometimes, after radiation treatment, your skin might look different and even change colour. The skin in the treated area could look and feel different, and blood vessels might become more visible. Your treated breast might feel firmer and look different in size shape and texture from your other breast.
- Discomfort: You may experience shooting pains in the breast, chest wall and armpit.
- Breastfeeding: you may not produce milk in the treated breast but the other breast will not be affected
- Rib fracture: Radiation can make your ribs under the treated breast weaker, which can cause a fracture. The chance of this happening is about 1%.
- Lung scarring (Fibrosis): A small part of the lung under your breast might get scarred from radiation. This scarring is rare and usually doesn’t cause any problems.
- Heart: Depending on where your treatment is, there is a small chance of heart damage and a slightly higher risk of heart disease. Your treatment team work hard to protect your heart from radiation by using specialized techniques. This means the risk is low
- Swelling of the arm (Lymphoedema): This is less common and it is usually mild or moderate.
- Nerve damage (Brachial Plexopathy): This is a rare side effect that might happen if the lymph nodes near your collarbone or armpit are treated. It can cause pain, numbness, and weakness in your arm and hand.
- Lung inflammation (Pneumonitis): This is an uncommon side effect that can happen after breast radiotherapy. It can cause a dry cough and shortness of breath. Sometimes, medicine is needed to help with these symptoms.
- Cancer-related fatigue: You might find you still have fatigue after your treatment has finished. For some people this can go on for months or years.
Rare or less common late effects
- Second Cancer: There is a very small chance that you could develop another type of cancer. This is rare, and depends on lots of different factors like age, area treated and radiation dose.
- Skin problems: In rare cases, your skin might break down and struggle to heal. It may become dry, painful and thickened, like scar tissue (known as radiation-induced morphea).
What can help with these late effects?
- Managing lymphoedema: Special exercises and treatments can help reduce swelling. Ask to speak to a lymphoedema specialist if this is a concern.
- Monitoring rare side effects: Talk to your treatment team as soon as you see any changes. This can help catch and treat any serious problems early.
- Managing cancer-related fatigue: Food and drink, keeping active, keeping a fatigue diary, medicine like steroids and physiotherapy may all be options for managing fatigue. Speak to your doctor or medical team for advice; and learn more about managing cancer-related fatigue.
- Drinking fluids: Drinking plenty of fluids such as water and squash can help with fatigue and tiredness caused by your treatment. It can also help flush out toxins in your body caused by treatment. You can try diluted juice if you don’t like water.
- Skin care: The skin in the treatment area will always be more sensitive to the sun. Always protect it by covering up and use a high factor sunblock.
- Keeping active: Gentle movement can help you feel better, both during and after treatment. Your clinical team can tell you what is safe for you to do.
- Alcohol use: Please follow the NHS guidelines on safe drinking levels and any instructions you get from your team on what is right for you, your diagnosis and your treatment. If in doubt, please ask your team.
- Stop smoking: If you are looking to stop or reduce smoking, there are services available to help you.
Always talk to your doctor or treatment team about any late effects you have. Even if they are not mentioned here. Everyone is different and experiences treatment differently. There may be ways they can help you reduce or manage symptoms.
Further information
Learn more about side effects and support here:
We’re Breast Cancer Now | Breast Cancer Now
Breast cancer in men | Breast Cancer Now
Women’s Health Concern | Confidential Advice, Reassurance and Education (womens-health-concern.org)
Learn more about radiotherapy consent forms here:
https://www.rcr.ac.uk/our-services/management-service-delivery/national-radiotherapy-consent-forms/
