A study looking at thinking and memory problems in men having hormone therapy for prostate cancer

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

Cancer type:

Prostate cancer





This study is looking at problems with concentration, thinking and memory in men having hormone therapy for prostate cancer.

Hormone therapy in men lowers the levels of the male sex hormone testosterone. One of the possible side effects of this is that some men experience memory loss or find it difficult to concentrate or carry out certain tasks that involve thinking. Doctors call this mild cognitive impairment.

Researchers want to know why this happens in some men and not others and whether the lack of testosterone causes any changes in the brain.

More about this trial

The trial team will use a PET scan to measure a specific protein called TSPO (translocator protein) in the brain. TSPO levels are raised when there is damage to the brain. Researchers will also measure levels of hormones in the body and ask men to complete tests and questionnaires.

You are unlikely to benefit from this study directly. The results will help the researchers find out whether hormone therapy causes changes in the brain. If so, they may then do a larger study to find out what causes these changes and which men are more likely to have problems.

In the future, this may help researchers develop treatments that can prevent or slow down these thinking and memory problems. It may also help doctors to provide better information about this side effect when discussing treatment choices with their patients.

Who can enter

You may be able to join this study if all of the following apply. You

You cannot join this study if any of these apply. You

  • Have had a stroke or brain injury in the past or you have a brain disorder such as dementia
  • Are unable to have an MRI scan or PET scan for medical reasons. You can’t have an MRI scan if you have a pacemaker or any metal implants in your body
  • Are unable to have a scan because you are not able to lie down for long periods of time (for example 90 minutes) or you would find an MRI scan too claustrophobic
  • Already had problems with thinking and memory before you started hormone therapy

Trial design

This is a pilot study. The researchers need 12 men to join the study.

The men taking part are put into two different groups, 6 men in each group. One group of men have concentration or memory problems. The other group of men do not have mild cognitive impairment, this is the control group Open a glossary item. All men will have the same tests and the results of the two groups will be compared.

At one of your routine follow up appointments you have some extra blood tests for the study. One of these will test for a specific gene called TSPO and another will measure your hormone levels. If you have this specific gene, you can take part in the study.

At the same appointment you are asked to complete some simple paper and computer based tests and questionnaires. For example, the tests will ask you to do some reading, recall pictures and words and there will be questions about making decisions. This takes about 1½ hours. The trial team will give you more information about this and offer technical support if necessary.

You then have some scans at a further appointment. You have an MRI scan which takes about an hour. In the first part you lie in the scanning machine, close your eyes and think of nothing in particular. This part of the scan looks at the structure of the brain.

During the second part of the scan, the researchers will show you pictures on a computer screen. You may just have to look at these pictures, or you may have to answer questions using a key pad. This part of the scan looks at how the brain works during particular activities.

You then have a PET scan. First, the doctor will put a small tube (cannula) into a vein in your hand or arm. They use it to give you a radioactive medicine to measure the levels of TSPO protein during the PET scan.

Your PET scan will take about 1½ hours. The aim of this scan is to see how much TSPO is present in the brain and where in the brain it is.

Hospital visits

You have the initial blood tests for this study during one of your routine follow up appointments, so don’t need to make an extra trip to the hospital.

You go to the Imaging Department at the Hammersmith Hospital in London to have your scans. This will take most of the day.

Side effects

Some people feel closed in (claustrophobic) when having an MRI scan. You have to lie quite still for both scans, but you can ask for a break if you are uncomfortable. MRI scans are very noisy, so you will have ear plugs or headphones to protect your hearing.

The injection you have for the PET scan is a radioactive medicine. But the amount of radiation it contains is very low and it goes away (decays) very quickly.

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 Paul D Abel

Supported by

Imanova Centre for Imaging Studies
Imperial College London

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.

Keith took part in a trial looking into hormone therapy

A picture of Keith

"Health wise I am feeling great. I am a big supporter of trials - it allows new treatments and drugs to be brought in.”

Last reviewed:

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