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

This trial is looking at hormone therapy with or without cryotherapy for prostate cancer that has come back in your prostate gland after radiotherapy. This trial is funded by Cancer Research UK.

Doctors may treat prostate cancer that has not spread to other parts of the body with radiotherapy. But if the cancer comes back after radiotherapy, they are unsure of the best way to treat it. One type of treatment you may have in this situation is cryotherapy. Cryotherapy uses freezing probes to kill cancerous tissue.

But we don’t know yet if cryotherapy is better than other treatments such as hormone therapy. Researchers want to find out if there are long term benefits to having cryotherapy and how it affects your quality of life.

In this trial, the researchers are comparing hormone therapy alone to cryotherapy followed by hormone therapy. The men taking part don’t start having hormone therapy straight away. They are monitored to begin with and start hormone therapy when their blood level of a protein called PSA goes up. This is called deferred treatment.

The aims of the trial are to

Find out how well cryotherapy before hormone therapy works for prostate cancer that has come back after radiotherapy
Learn more about the side effects

Recruitment

Start 15/06/2011

End 30/06/2016

Phase

Phase 3

Who can enter

You may be able to enter this trial if you

Have prostate cancer that has come back in your prostate gland after radiotherapy
Had either external radiotherapy or brachytherapy to treat prostate cancer that had not spread to another part of your body
Have prostate cancer that is either completely inside the prostate or has grown no further than just breaking through the covering of the prostate (stage T3a)
Have a PSA level of less than 20 ng/ml
Have satisfactory results of other blood tests
Are well enough to be up and about for at least half the day (performance status 0, 1 or 2)
Are at least 18 years old

You cannot enter this trial if you

Have any lymph nodes that are more than 1cm across when measured on an MRI scan
Have had combined radiotherapy and brachytherapy to your prostate gland
Have significant symptoms affecting the lower part of your urinary system including problems passing urine
Have had an operation called a transurethral resection to remove part of your prostate gland and an ultrasound scan shows that this has caused a defect to the tube carrying urine out of the body from your bladder (the urethra)
Had bad radiotherapy side effects caused by damage to your back passage (rectum)
Have had hormone therapy for prostate cancer that came back after radiotherapy
Have already had cryotherapy for prostate cancer
Have blood clotting problems
Have any other serious medical condition that the trial doctors think could affect you taking part
Have had any other cancer and your doctors think there is more than about a 1 in 3 (30%) chance of it coming back within 5 years

Trial design

This phase 3 trial aims to recruit 540 men. It is a randomised trial. The men taking part are put into treatment groups by a computer. Neither you nor your doctor will be able to decide which group you are in.

Group A have hormone therapy alone
Group B have cryotherapy and hormone therapy

The trial team will ask you to fill out a questionnaire before you start treatment and then

After 3 months, 6 months and 1 year
Once a year after that

The questionnaires will ask about any side effects you have had and about how you have been feeling. This is called a quality of life study.

Cryotherapy freezes cancer cells. You have cryotherapy under general anaesthetic. It takes about 2 hours. Using an ultrasound scan, your surgeon guides needles through your skin into your prostate gland. Very cold temperatures are produced by channelling gas through the needles at high pressure.

The day before your cryotherapy you have 2 enemas to empty your back passage. After cryotherapy you may have some discomfort, but the trial team will give you painkillers if needed.

Men in both groups have hormone therapy. This is likely to start when the level of PSA in your blood rises above 20 ng/ml. Your doctor will talk to you about when to start hormone therapy and what the best treatment will be for you. This may be tablets, injections or surgery to remove your testicles (orchidectomy).

Hospital visits

You will see the trial team and have some tests before you start treatment. The tests include

Physical examination
MRI scan
Bone scan
Blood tests including a PSA test
Urine test

You may need to have a biopsy if you have not already had one. Your doctor will take the biopsy during a transrectal ultrasound.

If you have cryotherapy, you may stay in hospital for 2 nights. When you go home, you will have a tube in your bladder to drain your urine into a bag. This is called a catheter. The catheter stays in place for about a week. Then you go back to hospital to have it taken out.

Men who have cryotherapy have another biopsy about 6 months later.

Everybody taking part will see the trial team after 3 months, 6 months and 1 year. After that you have a follow up appointment, bone scan and MRI scan once a year for up to 7 years.

You have PSA tests every 3 months for the first year and then once a year after that.

Side effects

The possible side effects of cryotherapy for prostate cancer include

Urinary problems such as leaking or difficulty passing urine
Problems getting an erection (impotence)

Rarely, cryotherapy to the prostate gland can cause a hole called a fistula to form between your bowel and the tube carrying urine out your body (your urethra). If this happens, you may have surgery to repair it. If you develop a fistula, it may be necessary to create an opening to the outside of your body (a stoma) which is covered with a bag.

The side effects of hormone therapy for prostate cancer include