A trial looking at how much tissue to remove during surgery for melanoma skin cancer (MelMarT-II)

Cancer type:

Skin cancer




Phase 3

This trial is looking at the amount of tissue a surgeon removes during surgery for melanoma.

It is for people who have melanoma that hasn’t spread. This is stage 2 melanoma.

More about this trial

Doctors diagnose melanoma by removing the abnormal mole or area of skin. They send it to the laboratory to check if it's a melanoma and how thick it is.

You have surgery to remove more tissue if it is a melanoma. This is a wide local excision. The surgeon removes a further area of skin and tissue from around where the melanoma was. This is called a margin Open a glossary item. This helps to reduce the risk of it coming back.

Currently, doctors are uncertain how much skin to remove from around a melanoma. Guidelines in different countries vary in their recommendations on this. For stage 2 melanoma in the UK, the current guidance is a 2 to 3cm margin. 

Previous research suggested that a 1cm margin may be enough to reduce the risk of melanoma coming back in the same area. This needs to be tested in a trial of more people before it becomes standard practice.

The main aims of the trial are to find out:

  • if a 1cm margin is as safe as a 2cm margin
  • if a 1cm margin can reduce the need to have extra surgery such as a skin graft
  • if there is a difference in the side effects 
  • more about quality of life Open a glossary item

Who can enter

The following bullet points are a summary of the entry conditions for this trial. Talk to your doctor or the trial 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 trial if all of the following apply.

  • You have melanoma skin cancer that is only in the skin and there is no sign that it has spread to the lymph nodes Open a glossary item or other parts of the body (stage 2 melanoma).
  • You have a melanoma that is more than 2mm thick and the outer layer of the skin isn’t broken (ulcerated) or the melanoma is more than 1mm thick and is ulcerated.
  • It is possible to remove a further 2cm margin around the melanoma biopsy scar. 
  • Your surgical team is able to do the wide local excision and sentinel lymph node biopsy within 120 days of your original melanoma diagnosis. You may need to discuss this further with your surgical team.
  • You are fit and active but might not be able to carry out heavy physical work (performance status of 0 or 1).
  • You are at least 18 years old.

Who can’t take part

Cancer related
You cannot join this trial if:

  • you have cancer cells in the tissues around the melanoma, in the lymph nodes or it has spread to another part of the body
  • your doctor can’t be sure you have melanoma
  • you have already had a wide local excision to remove the melanoma 
  • you can’t have a sentinel lymph node biopsy to see how far the cancer has spread
  • you have a rare type of melanoma called desmoplastic or neurotropic melanoma or you have a type of melanoma that starts in the skin under a nail (subungual melanoma). Your doctor will know this.  
  • you have melanoma but it isn’t possible to work out the margins for any reason. Your doctor will know this. 
  • you have had melanoma in the past or you have another melanoma somewhere else on the body
  • you have melanoma that started between the knuckles and fingertips, on the tip of the nose, on the eyelids, in the mucosal membranes Open a glossary item or in the organs inside the body
  • you have had surgery in the past for another reason to remove the lymph nodes or you have had a sentinel node biopsy in the past 
  • you are going to have radiotherapy to where the melanoma started after having the wide local excision
  • you have had another cancer that has got worse or needed treatment in the past 5 years unless it has a low chance of coming back. You can join if it was successfully treated non melanoma skin cancer, Open a glossary item cervical cancer or cancer of the womb. Open a glossary item

Medical and other conditions 
You cannot join this trial if any of these apply. You:

  • have had an organ transplant Open a glossary item in the past
  • have had treatment that damps down the immune system Open a glossary item. This includes steroids Open a glossary item unless it was a low dose.

You might be able to take part if you are pregnant. This depends on when you can have your surgery. You can talk to the surgical team about this if it applies to you.

Trial design

This phase 3 trial is taking place worldwide. The team need about 2,998 people to take part. This includes 750 from the UK. 

It is a randomised trial. You are put into a group by a computer. Neither you nor your doctor will be able to decide which group you are in. 

There are 2 surgery groups. You have one of the following:

  • one group will have a 1cm wide local excision
  • one group will have a 2cm wide local excision 

There are equal numbers of people in the two groups

At the same time as the wide local excision, everyone will have an operation to remove some lymph glands closest to the melanoma. This is a sentinel node biopsy. It is part of your routine treatment.

The trial team ask you to fill out a few questionnaires:

  • before you have surgery 
  • at set times after surgery 

Some of the questionnaires ask about side effects, pain and how you are feeling. This is a quality of life study

Some questionnaires ask about:

  • GP appointments
  • medications you take
  • hospital admissions
  • outpatient visits
  • contact with other healthcare professionals

They also ask about any help you need day to day, time off work or usual activities, and any effect on your income.

Hospital visits

You see the doctor before you can take part. During an initial visit the doctor will check if you are suitable for the study. You also have a physical examination Open a glossary item.  

The doctor will ask you questions about any surgical complications or new diagnoses since your last visit. They will also check your medical history Open a glossary item and for any changes in your medications.

You have a blood test if this is routine at your hospital.

Before your surgery you:

  • complete questionnaires
  • have a photo taken of the melanoma

After surgery you see the doctor for a check up at:

  • 3 months
  • 6 months
  • 1 year 
  • 18 months
  • 2 years and then 
  • once a year until the end of the trial

This follow up schedule is similar to one you would have had if you didn’t take part in this trial. Any other clinical visits your doctor feels are necessary, will take place as normal.

Side effects

The trial team monitor you during the trial. Contact your advice line or tell your doctor or nurse if any side effects are bad or not getting better. 
The most common side effects of having a wide local excision include:

  • discomfort and bruising
  • minor infections 
  • bleeding
  • wound pain
  • scarring

Your doctor will talk to you about all the possible side effects before you join the trial. 

We have more information about surgery for melanoma.



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 Marc Moncrieff

Supported by

National Institute for Health Research (NIHR)
Norfolk & Norwich University Hospitals NHS Trust
Melanoma and Skin Cancer Trials (MASC Trials)
Surgical Trials Intervention Unit (SITU)

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.

Charlie took part in a trial to try new treatments

A picture of Charlie

“I think it’s really important that people keep signing up to these type of trials to push research forward.”

Last reviewed:

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