A study looking at thinking, memory and concentration problems in men having hormone treatment for prostate cancer (CogCan)

Please note - this trial is no longer recruiting patients. We hope to add results when they are available.

Cancer type:

Prostate cancer





Problems with thinking, concentration and memory are called cognitive problems. 

This study is for men who are going to have treatment to lower the levels of the male sex hormone testosterone (hormone therapy). Researchers are also looking for some men with prostate cancer who will not have hormone therapy. This is the control group.

More about this trial

Hormone therapy (or androgen deprivation therapy) is a treatment for prostate cancer. You can have it on its own, or in combination with other treatments such as radiotherapy

One of the possible side effects of hormone therapy is problems with thinking. You may also have memory loss or find it difficult to concentrate. Doctors call these changes in memory and thought processes mild cognitive impairment. 

In this study, researchers want to learn more about these side effects. They will use tests that measure thinking skills (cognitive tests) and brain MRI scans
The main aim of this study is to learn more about how hormone therapy affects the thinking skills of men with prostate cancer. 

Who can enter

The following bullet points list the entry conditions for this study. Talk to your doctor or the study team if you are unsure about any of these. They will be able to advise you. 

Who can take part

You may be able to join this study if you are a man and all of the following apply. You:

  • have prostate cancer  
  • can speak and write in English 
  • are aged between 50 and 85 years old 

Who can’t take part

You cannot join this study if any of these apply. 

Cancer related

  • have had hormone therapy in the past
  • have a benign prostate tumour
  • have prostate cancer that has spread to other parts of the body (metastatic)
  • have had treatment for prostate cancer that reached your whole body (systemic treatment) and doctors think this may have affected your thinking skills

Medical conditions

  • have problems with thinking and memory 
  • have had a stroke
  • have had fits (seizures) in the past 
  • have dementia or Alzheimer’s disease
  • take illegal drugs 

Trial design

The researchers hope that around 153 men with prostate cancer will take part. They need:

  • 102 men who are going to have hormone therapy
  • 51 men who will not have hormone therapy (control group)

Everyone taking part meets with a member of the study team. They will ask you some questions to test your memory and attention. This is to make sure that you don’t have any problems with your thinking skills. This takes about an hour.

You will not be able to continue in this study if the study team finds that you have any difficulties. They will discuss this with you and let your GP know so they can offer you any support you need. 

You continue in this study if the researchers don’t find any problems. You will have a blood test. The study team wants to look for certain proteins (genetic markers) that can tell if someone is at risk of having problems with their thinking.  

You then complete some simple paper based tests and questionnaires. For example, the tests will ask you to recall pictures and words, and complete some reading. This takes about 4 and a half hours, but you can have breaks during the test so it’s not too tiring.

You have a brain MRI scan either on the same day or, if you prefer, within 2 weeks. This takes around an hour. The study team will also ask you to give a saliva sample. They want to measure the levels of hormone testosterone in your body. 

After 6 months, you complete more paper based tests and questionnaires, and have another brain MRI scan. The study team asks you for another saliva sample. 

Another 6 months later, you complete the final set of paper based tests and questionnaires. You also give another saliva sample.

Hospital visits

You go to the University of Birmingham or Aston University to see the study team and to have the MRI scans. You have up to 5 visits in total and you will be reimbursed for your time and travel. The visits take place over a 12 month period.

There is more information about this on the CogCan research study website.

Side effects

The study team might find problems with your memory and attention. Finding out that you have problems with your thinking can be upsetting. But the team will be able to ask your GP to investigate this, so that you can get the support you need. 

You can also feel unwell after the blood tests, but this is rare. The study team will tell you about all the possible side effects before you take part in this study. 

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Professor Elizabeth Grunfeld

Supported by

Birkbeck University of London
Coventry University 
Aston University
Kings College London
Prostate Cancer UK


If you have questions about the trial please contact our cancer information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:


Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Last reviewed:

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