A trial of cryotherapy and hormone therapy for prostate cancer that has come back after radiotherapy (CROP)

Cancer type:

Prostate cancer




Phase 3

This trial looked at hormone therapy and cryotherapy for prostate cancer that has come back in your prostate gland after radiotherapy. The trial was supported by Cancer Research UK.

Doctors may treat prostate cancer that hasn’t spread to another part of the body with radiotherapy. But if the cancer comes back they are unsure of the best way to treat it. You may have one type of treatment called hormone therapy or something called cryotherapy. Cryotherapy uses freezing probes to kill cancerous tissue.

In this trial, the researchers compared hormone therapy with cryotherapy followed by hormone therapy.

The aims of the trial were to find out

  • How well cryotherapy before hormone therapy works for men with prostate cancer that has come back after radiotherapy
  • More about the side effects

Summary of results

The trial team found that it wasn’t possible to do this trial. They couldn’t open the trial at enough hospitals and it was difficult to get men to join.

The planned treatments in this trial were

  • Cryotherapy followed by hormone therapy
  • Hormone therapy

The men taking part in the hormone therapy group weren't going to have treatment straight away. They were monitored to begin with and would start hormone therapy when their blood level of a protein called PSA went up.

The trial aimed to recruit 540 men. It was going to run at a number of hospitals, but only 4 opened. The researchers screened 39 men to see if they were eligible to take part. They found that most of the men didn’t want to be randomised. In a randomised trial the people taking part are put into 2 treatment groups by a computer. Neither the men nor their doctor could decide which group they were in. Of the 28 men who were eligible,

  • 7 agreed to be randomised
  • 21 didn’t agree to be randomised

The trial team found that the men didn’t agree to be randomised because

  • The researchers had difficulties explaining that the treatments worked  as well as each other
  • Most of the men wanted to have cryotherapy
  • The men may have thought that having treatment straight away was better than waiting for treatment. Most of them didn’t find it acceptable that they would have to wait for treatment if they were randomised to have hormone therapy alone.

Unfortunately the trial had to close earlier than planned because of the recruitment problems.

We have based this summary on information from the team who ran the trial. The information they sent us has been reviewed by independent specialists (peer reviewed Open a glossary item) and published in a medical journal. The figures we quote above were provided by the trial team. We have not analysed the data ourselves.

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 Hing Y. Leung

Supported by

Cancer Research UK
NIHR Clinical Research Network: Cancer
NHS Greater Glasgow and Clyde

Other information

This is Cancer Research UK trial number CRUK/10/048.

Questions about cancer? Contact our information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:

Oracle 6915

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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