A trial looking at improving usual treatment for newly diagnosed Merkel cell cancer (Rational Compare trial and Rational Review study)

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

Cancer type:

Neuroendocrine tumour (NET)
Non melanoma skin cancer
Skin cancer




Phase 3

This research is for people with Merkel cell cancer who are having surgery or radiotherapy.

More about this trial

Merkel cell cancer (also known as MCC) is a rare type of skin cancer. Surgery or radiotherapy is the usual first treatment. But doctors don’t know which treatment works best to stop the cancer coming back. Or which has the fewest side effects.

Researchers want to improve treatment for MCC so that it is less likely to come back after treatment. They also want to improve how people feel during and after treatment.

There are 2 parts to this research:

  • part 1 is the main trial called the Rational Compare trial
  • part 2 is a smaller study called the Rational Review study – it is for people who don’t want to or might not be suitable to join part 1

The main aim of the Rational Compare trial is compare radiotherapy with surgery to see which works best.

Other research aims include:

  • collecting information about treatments people have, their cancer and how well treatment works
  • learning more about side effects and quality of life Open a glossary item

Who can enter

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

You might be able to take part in this research if all of the following apply.

  • You have newly diagnosed Merkel cell cancer
  • You have had all the tests to check the stage Open a glossary item of your cancer  - such as CT scans or MRI scans of lymph nodes Open a glossary item and organs such as your liver (to find out if there is any cancer spread)
  • Your cancer hasn’t spread to a different part of the body
  • Your doctors plan to treat the cancer with surgery or radiotherapy – (if you can’t join part 1 you might have chemotherapy or immunotherapy Open a glossary item)
  • There is a sample of tissue available for the research team to do some tests

The following must also apply to join part 1 (the Rational Compare Trial).

  • Your doctors think the cancer can be completely removed with surgery (using a surgical method called a wide local excision) or successfully treated with radiotherapy
  • Your doctors think you can have either radiotherapy or surgery
  • It is possible to have clear margins Open a glossary item of at least 1 cm with either surgery or radiotherap

You cannot join part 1 (the Rational Compare Trial) if the following apply.

  • You have already had surgery or radiotherapy to the area where the cancer started (the primary tumour)
  • You are due to have chemotherapy, biological therapy Open a glossary item or immunotherapy Open a glossary item

Trial design

This research is in 2 parts:

  • part 1 is the main phase 3 trial - researchers need 250 people to take part
  • part 2 is a smaller study for 150 people who aren’t suitable for the main trial

Before joining this research, you have some tests to diagnose your cancer and help doctors decide how best to treat it. Your specialist team will explain the results of these tests and talk to you about possible treatments.

If they think you might benefit equally from either surgery or radiotherapy you might be able to join the Rational Compare trial. This is randomised. You are put into 1 of 2 treatment groups by a computer.

  • One group have surgery
  • The other group have radiotherapy


Neither you nor your doctor will be able to decide which group you are in.

If you aren’t suitable for part 1, you might be able to join the part 2 (the Rational Review study). In this study, you and your doctors decide the best treatment for you.

Some people might need to have radiotherapy to the scar after surgery. Your doctor will tell you more if this applies.

It is possible you might have some further tests or treatment. These aren’t part of the research but could be needed because of the treatment you have. The trial team plan to collect information about all these other possible tests and treatments. They hope this might help improve treatment for other people with MCC in the future.

Samples for research
Everyone taking part has some extra blood tests before and after treatment. Where possible you have these at the same time as your routine blood tests.

The research team also ask to look at a sample of cancer (biopsy Open a glossary item) taken when you were first diagnosed. They plan to use the samples to look for changes in the immune system Open a glossary item and compare this to how people respond to treatment. This might help predict which treatments work best for people in the future.   

Any leftover samples will be stored and used for future research projects.

Quality of life
Everybody joining part 1 will be asked to fill out some questionnaires before starting treatment, at set times during the trial and after finishing treatment. The questionnaire will ask about how you have been feeling. This is called a quality of life study.

Hospital visits

You will have had all the standard tests done before joining this research. But you might have another CT scan if you haven’t had one within 8 weeks of starting the trial.

If you have surgery, it might be possible to have it as a day case. If this isn’t possible the research team can tell you more about how long you need to stay in hospital.

If you have radiotherapy, you have it every weekday (Monday to Friday) for 6 weeks.

Follow up
For both parts of the research you:

  • give a blood sample 3 months after you join
  • see the research team every 3 months for a check up for 2 years
  • have a PET-CT scan 1 or 2 years after treatment 

Side effects

The main side effects of surgery include:

  • risk of bleeding
  • infection
  • temporary numbness and lumpiness in the scar area

The most common side effects of radiotherapy to the skin are:

  • redness and soreness but this usually settles after 6 to 8 weeks
  • mild skin changes, for example, the area treated might be lighter in colour than the surrounding skin

Your doctor will be able to tell you if you should expect any other side effects due to the position of your Merkel cell cancer.

We have more information on the general side effects of radiotherapy.

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

Dr Neil Steven

Supported by

NIHR Efficacy and Mechanism Evaluation (EME) Programme
Medical Research Council (MRC)
University of Birmingham

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.

Over 60,000 cancer patients enrolled on clinical trials in the UK last year.

Last reviewed:

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