A study looking at metformin before surgery for womb cancer

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

Cancer type:

Womb (uterine or endometrial) cancer




Phase 3

This study is looking at the diabetes drug metformin for womb cancer and a condition affecting the lining of the womb called endometrial hyperplasia.

Endometrial hyperplasia is a precancerous condition that increases your risk of womb cancer.

More about this trial

One of the drugs doctors can use to treat diabetes is called metformin. We know from earlier laboratory research, that metformin can slow down the growth of some cancers including womb cancer.

In this study, researchers want to find out more about having metformin before surgery for womb cancer or endometrial hyperplasia.

The aim of the study is to see if metformin before surgery helps to slow the growth of womb cancer or endometrial hyperplasia.

Joining this study will not change your treatment, and you may not get any direct benefit from taking part. The researchers hope that the information they collect will help to improve treatment for women with womb cancer or endometrial hyperplasia in the future.

Who can enter

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

  • Have womb cancer that is linked to too much of the hormone oestrogen Open a glossary item and is slow growing (this is known as type 1 endometriod cancer), or you have a precancerous condition called endometrial hyperplasia
  • Are having an operation to remove your womb (a hysterectomy) in the next 5 weeks
  • Are at least 18 years old

You cannot join this study if any of these apply.

  • You are having chemotherapy or treatment with drugs called mTOR inhibitors (your doctor can tell you more about this)
  • You have diabetes and you have insulin injections or take tablets to control your condition
  • You are already having metformin
  • Your kidneys or liver aren’t working well
  • You have problems with alcohol addiction that the trial team think would affect you taking part
  • You are known to be very sensitive to drugs that are used to treat diabetes (your doctor can tell you more about this)

Trial design

The researchers need 95 women to take part in the study. It is randomised. The women 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. And neither of you will know which group you are in. This is called a double blind trial.

  • Women in one group have metformin before surgery
  • Women in the other group have a dummy drug (placebo Open a glossary item) before surgery

You have metformin (or the dummy drug) once a day for 3 days and then twice a day until the evening before your surgery. You have the tablets for up to 5 weeks depending on the date of your operation.

After you have been taking the tablets for a few days, a member of the study team will phone you to see how you are managing with your treatment. You can also contact the study team if you have any problems during this time.

The researchers will ask to take a sample of your cancer (a biopsy Open a glossary item) before you start treatment. If you have already had a sample taken, the researchers might be able to use the stored sample for their tests. They will compare this sample with a sample that is removed when you have surgery to remove your womb. This is to see if metformin has helped to treat slow the growth of your womb cancer or endometrial hyperplasia.

Hospital visits

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

  • Blood tests
  • Physical examination
  • Urine tests
  • Taking a sample of tissue (a biopsy) Open a glossary item from your womb

You have the blood and urine tests repeated when you go to hospital to have your surgery.

Side effects

The side effects of metformin are usually mild and include

  • Feeling or being sick
  • Tummy pain
  • Diarrhoea
  • Loss of appetite
  • Taste changes
  • Skin rash or itchy skin

Alcohol can interact with metformin and the study team suggest that you don’t drink alcohol while having metformin.

Very rarely, metformin can cause liver problems or an increase in lactic acid Open a glossary item in your blood. This is called lactic acidosis and can lead to problems such as rapid breathing, feeling and being sick and muscle weakness.

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 Emma Crosbie

Supported by

Central Manchester University Hospital NHS Foundation Trust
NIHR Clinical Research Network: Cancer

Questions about cancer? Contact our 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.

Cara took part in a clinical trial

A picture of Cara

"I am glad that taking part in a trial might help others on their own cancer journey.”

Last reviewed:

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