What are cancer-related cognitive changes?

Changes in memory or concentration and the ability to think clearly during cancer treatment are often called cancer-related cognitive changes (CRCC) or chemo brain.

This is because the symptoms were first linked to chemotherapy. But changes in memory and concentration can affect people with cancer who have not had chemotherapy.

Symptoms of cognitive changes

Any problems with concentration or memory are usually temporary and mild. But while they last, they can be frustrating and interfere with your normal activities. They may delay some people from going back to work, school or to social events.

Common symptoms include:

  • being unusually disorganised
  • difficulty doing more than one thing at a time
  • getting distracted more easily
  • finding it hard to remember things
  • feeling like you can’t think clearly
  • extreme tiredness (fatigue).

If you have these symptoms, you should talk to your doctor about them. It can be helpful to keep a record of your symptoms to show the doctor.

Who gets cognitive changes?

It is not clear how many people develop problems with their concentration or memory during or after cancer treatment. Different research studies suggest quite different figures. But as many as 78 in 100 (78%) of people with cancer may be affected. It can affect both men and women.

Causes and risk factors

The causes are unclear. Research suggests that it may be caused by a combination of factors. Some cancers, such as brain tumours, have a higher risk of causing problems with memory and thinking.

Other risk factors include:

  • cancer treatments, including chemotherapy, hormonal therapy, radiotherapy and surgery
  • treatment to the brain, such as chemotherapy into the fluid around the spinal cord (intrathecal chemotherapy) or radiotherapy to the brain
  • high-dose treatment with chemotherapy or radiotherapy
  • side effects of cancer treatment, such as infection, low number of red blood cells (anaemia), extreme tiredness (fatigue), sleep problems, poor nutrition and menopause
  • emotional reactions to cancer and treatment, such as anxiety and depression
  • non-cancer drugs such as painkillers or anti-sickness (anti-emetic) medicines.

It is worth remembering that the benefits of your cancer treatment will usually far outweigh the risk of developing CRCC. Your doctor or nurse will be happy to talk about your treatment with you if you are worried.

Can cognitive changes be prevented or treated?

It is difficult to prevent or treat problems with memory or concentration because it is not clear what causes them. Research is going on to find ways to prevent cognitive changes and effective treatments for people who have them.

Coping with cognitive changes

Problems with concentration or memory are often mild, and often get better with time. But for some people, symptoms can continue for years after treatment.

There are a number of things you can do to help yourself. Your doctor or specialist nurse can give you more information and support.

  • Keep a diary

    Keeping a record of your symptoms may help you work out if certain things make your memory worse. For example, you may notice that symptoms seem worse first thing in the morning, or when you are tired or hungry. This can help you to plan your day so that you do more difficult tasks when you feel at your best.

  • Use memory aides

    Writing down information at the time can help you remember important things later:

    • Make lists, such as shopping lists or to-do lists, so that you feel confident you will not forget anything.
    • Use Post-it® notes with reminders on them and put them where you can easily see them.
    • Use a diary or calendar. There may be a calendar app on your mobile phone.
    • Carry a notebook and make notes during conversations, after meeting new people or after making arrangements.
  • Mental exercises

    Memory exercises may help to train your brain and improve your memory and concentration. You can help keep your mind active by doing crosswords, word games or number puzzles like Sudoku.

  • Keep active

    Being more physically active can help you feel more alert and reduce tiredness (fatigue).

  • Reduce stress

    Stressful situations can affect everyone’s memory. Relaxation can help to reduce stress and may help to improve your memory and concentration. Do some activities that help you relax, such as listening to music or going for a walk. You could do some relaxation exercises or try using relaxation CDs or DVDs.

  • Learn new habits
    • Keep things simple – do not take on too much. Try to do one thing at a time.
    • Develop a manageable daily routine and try to keep to it. 
    • Avoid distractions – for example, if you need to concentrate on something, sit in a quiet area and turn off the TV and radio.
    • Eat a healthy, well-balanced diet, especially lots of fresh fruit and vegetables. Your doctor or nurse can give you advice or refer you to a dietitian, if needed. 
    • Take regular breaks and get plenty of rest and sleep. 
    • Seek support from others in a similar situation – perhaps join an online forum such as our Online Community or a local support group.     

Research into cancer-related cognitive changes

Research is being done to find out:

  • which chemotherapy drugs or combinations of drugs affect cognitive functioning
  • whether other cancer treatments affect cognitive functioning
  • what can be done to reduce the risk
  • which treatments can be used to improve symptoms.

You may be asked to take part in a research trial, and your doctor or nurse will explain fully what this involves. You do not have to take part in the trial if you do not want to, and you do not have to give a reason why.

Getting support

Talk to family and friends

Many people find that talking to family and friends about what they are going through can help. Changes in memory or concentration are often less obvious than other side effects of treatment, so you may need to explain how you are feeling and how it is affecting you.

Your family and friends may not be aware these problems can be a side effect of treatment. If they have noticed any symptoms, they may be relieved to know that these are fairly common and usually get better with time.

Talk to your doctor or nurse

It is a good idea to write down how these changes are affecting you before you see your doctor. If your memory is bad, it may help to take someone with you or to record the conversation (with your doctor’s permission) so that you do not forget anything. Your doctor may:

  • check for side effects of treatment (such as anaemia) that could be contributing to your symptoms
  • advise whether any of your medicines could be making symptoms worse
  • refer you to other people for specialist help, such as a counsellor or a support group.

Other support

Our cancer support specialists can offer you support. They can also give you details of support organisations and counselling services in your area.

How we can help

Macmillan Cancer Support Line
The Macmillan Support Line offers confidential support to people living with cancer and their loved ones. If you need to talk, we'll listen.
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