Research looking at cognitive changes (chemo brain)

Cognitive changes include problems with memory, concentration and how a person can think. Your doctor might call this cancer related cognitive impairment. It is also known as chemo brain or chemo fog. 

Research into diagnosing and treating cognitive changes caused by cancer or its treatment is ongoing.

Research and clinical trials

All cancer treatments must be fully researched before they can be used for everyone. This is so we can be sure that:

  • they work
  • they work better than the treatments already available
  • they are safe

Research into diagnosing cognitive changes


In the CICARO study, researchers look at cognitive changes in people with ovarian and breast cancer. The researchers want to measure cognitive function before and after chemotherapy with paclitaxel. They are using neuropsychological tests in this research. They will compare the results of the test with those of people with:

  • benign Open a glossary item gynaecological tumours Open a glossary item
  • breast cancer, who did not have chemotherapy treatment

In another study, researchers look at brain changes. This is in people undergoing chemotherapy for bowel (colon or rectal) cancer. The researchers will use the information to identify helpful tests. They will use the tests to diagnose people at risk of developing difficulties with thinking and memory.

Researchers are also looking at using advanced MRI scans to see changes that happen to the brain. This is in older people with breast cancer and who are having chemotherapy. They want to learn more about the brain changes that happen with severe side effects of chemotherapy.

In the TLC study, researchers look at older people with breast cancer having systemic treatment Open a glossary item. The researchers are looking at cognitive changes and how these changes affect quality of life (QOL).

Hormone therapy

In one study, researchers look at cognitive function in men with prostate cancer. They are interested in men having treatment with hormone therapies. These are drugs such as abiraterone acetate and enzalutamide. The researchers are using MRI Open a glossary item scans. They are looking for changes in the brain’s structure or activity related to treatment. And how these changes might affect cognitive function.

The researchers are also looking for genetic Open a glossary item changes. These changes might make men more or less sensitive to cognitive changes during treatment for prostate cancer.


Radiotherapy to treat benign Open a glossary item and malignant Open a glossary itembrain tumours can cause cognitive changes. This can be in areas not related to the areas affected by radiotherapy. In one study, researchers use MRI scans before treatment starts, at 6 and 12 months. The scans help them to look at changes in the brain. The researchers are interested in brain areas called the limbic system and thalamus. These areas are involved with memory.

Researchers look at cognitive changes in people with brain metastases in another study. Doctors treat brain metastases with stereotactic radiosurgery (SRS) Open a glossary item or whole brain radiotherapy (WBRT). The researchers are looking at using MRI scans in this study. The scans will help them to find radiological biomarkers Open a glossary item for cognitive changes. People taking part will have their cognitive function measured:

  • before treatment
  • at 2 years after treatment

Research into treating cognitive changes


In one study, researchers look at testing a memory training program. It is for people with breast cancer who have problems with memory. This is after receiving chemotherapy. The researchers want to see if people taking part can improve their memory and attention problems.

They are using either one of two versions of the training program. One version is called Cogmed Working Memory Training. The other program has the same exercises but is less difficult.


The CLARITY study is a pilot study Open a glossary item. The researchers are looking at a specific exercise program. They want to know whether it can improve brain and heart function. The study is for people having chemotherapy for breast cancer. The researchers are looking at high intensity interval training (HIIT). This is a way of training. They want to know if it can improve:

  • cognitive function
  • heart and lung fitness

Cognitive changes caused by cancer can interfere with normal life and worsen quality of life. Older people having stem cell transplants Open a glossary item are at high risk for cognitive problems. Previous research showed that physical activity improves cognitive function. This was in:

  • older people
  • survivors of other cancers

In the PROACTIVE study, researchers look at increasing physical activity. They want to know if it can improve cognitive function. They are looking at this in the above group of people. The researchers want to adapt and test a physical activity intervention already based on evidence.

Diet and cognitive training

In this research study, researchers look at people who had blood cancer. They want to see whether they can use a cognitive intervention program. One group of people in the trial will use:

  • a ketogenic diet meal replacement
  • online cognitive training

The researchers are comparing this group with another group that doesn't use it. They also want to know how long the effects of the program last.

Online training programs

In the Telehealth and Memory Study (TAMS), researchers look at how well Memory and Attention Adaptation Training (MAAT) works. MAAT is a cognitive behavioural therapy (CBT). It treats cognitive changes caused by chemotherapy. It is for people who have had breast cancer.

Researchers look at cognitive interventions in the BrainHealth in Breast Cancer Survivors study. This is in people who have noticed changes in their thinking since their treatment. The researchers want to know:

  • how well they work
  • whether it improves brain health and performance

International Cognition and Cancer Task Force (ICCTF)

In 2006 a group of specialists and patients set up the International Cognition and Cancer Task Force (ICCTF). The group aims to guide future research. They also give information to patients and doctors. This is on how to manage the symptoms of cognitive impairment.

Its members carry out local, national and international research. They have working groups looking at different areas of research. These include:

  • the best way to identify and assess those people who have (or who are at risk of) cognitive impairment
  • research possible treatments that can then be tested in clinical trials

    Accessed June 2023

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact with details of the particular issue you are interested in if you need additional references for this information.

Last reviewed: 
27 Jun 2023
Next review due: 
27 Jun 2026

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