What is stem cell or bone marrow transplant?

Stem cell and bone marrow transplants are a type of treatment that is sometimes used to treat:

To understand how stem cell and bone marrow transplants work, it helps to know about the bone marrow and stem cells.

What is bone marrow?

Bone marrow is part of our immune system, which protects us from infection and disease. It is found inside our bones, mainly in the hip bone (pelvis) and the breastbone. The bone marrow is where stem cells are made.

Illustration of bone marrow, stem cells and blood cells
Image: Bone marrow and blood cells


What are stem cells?

Stem cells are blood cells at the earliest stage of development. All our blood cells develop from stem cells in the bone marrow. Stem cells stay inside the bone marrow. When the blood cells are fully developed, they go into the bloodstream.

Blood cells do not live long. The bone marrow normally makes millions of new blood cells every day to replace blood cells as they are needed.

The three main types of blood cell are:

  • red blood cells – these contain haemoglobin (Hb), which carries oxygen from the lungs to all the cells in our body
  • platelets – these help the blood to clot and prevent bleeding and bruising
  • white blood cells – these fight and prevent infection.

There are two main types of white blood cell. These are called neutrophils and lymphocytes. Neutrophils are the most common. You will hear your doctor or nurse talk about your neutrophil count during your treatment.

Autologous stem cell transplants (your own cells)

An autologous stem cell transplant involves collecting and storing your own stem cells. This means you can have much higher doses than usual of chemotherapy and sometimes radiotherapy to treat the cancer.

The high-dose treatment destroys the cancer cells, but it also affects your healthy blood cells. After the high-dose treatment, you are given your stem cells back through a drip (infusion). The stem cells travel through your blood to your bone marrow. They then begin to make new blood cells.

Donor stem cell (allogeneic) transplants

A donor stem cell transplant aims to replace bone marrow that is no longer working properly with healthy stem cells from another person (the donor). This type of transplant is also called an allogeneic stem cell transplant.

You have chemotherapy and sometimes other treatments to destroy your own immune system. Then you are given the donor’s stem cells through a drip (infusion). The donor’s stem cells find their way to your bone marrow and start to grow and make healthy new blood cells.

Preparing for a stem cell treatment

Having a stem cell transplant is physically demanding. Your transplant team need to make sure that you are well enough to cope with it. They will ask you questions about your health and lifestyle and do tests to check your general health. They will give you advice on how best to prepare yourself. You may see other health professionals before you go into hospital. This could include a dietitian or a physiotherapist.

Your team will talk to you about:

  • Fitness

    If you lost weight with previous treatment, ask for advice on gaining weight. You may also have lost some fitness. Even taking regular short walks will help you to feel stronger. All this can help you with your recovery.

  • Your feelings

    A stem cell transplant may be emotionally difficult for some people. You may have complex feelings about it. Having support from family, friends and your healthcare team is helpful. There may be a counsellor who can help you cope with these feelings before your treatment. They can also support you during your stay in hospital.

    Some people find it helps to talk to someone who has already had a stem cell transplant. Your specialist might be able to put you in contact with someone.

    You can also use Macmillan’s Online Community to meet people who are going through similar experiences to you. Visit our stem cell transplants for blood cancer forum to talk with people who have had stem cell transplants, share your experience, and ask an expert your questions. 

  • Coping with risk of infection

    When you go home you will be at risk of infection. If you live with other people, there may be things they can do to help protect you. For example, this could mean making sure they have the flu vaccination when it is available. They could also make sure any children living with you are up-to-date with any vaccinations.

  • Work and money

    If you work, you will not be able to go back straight away after your treatment. Being unable to work may affect your finances. It may be helpful to talk to one of Macmillan’s benefit advisers or financial guides about help with money. Call 0808 808 00 00 to speak to an adviser.

  • Stopping smoking

    If you smoke, your transplant team will advise you to stop. This is because smoking increases the risk of complications and long-term side effects. Stopping smoking can help your recovery.

  • Dental care

    You will be asked to visit a dentist for a check-up, and to have any dental work you need before treatment starts. Making sure your teeth or dentures are in good condition reduces the risk of problems with your mouth during treatment.

  • Fertility

    A stem cell or bone marrow transplant may affect whether you can get pregnant or make someone pregnant. If you are worried about your fertility, it is very important to talk to your specialist doctor or nurse. They can refer you to a fertility specialist to discuss possible options to preserve your fertility.

  • Packing for hospital

    The nurses will suggest what to take to keep you busy and make you more comfortable. Most hospitals have TVs, but you may also want to take a tablet or laptop, books, magazines or games. You may also want to take some personal things, like photos, pictures and a clean blanket or pillow. Take some comfortable, loose-fitting clothes. Soft, cotton materials are best. Tops with buttons make it easier when you are being examined. An eye mask and ear plugs may help you sleep better. Ask the nurses for advice about the toiletries you should bring.

    Before your treatment, you can usually visit the unit. It is a good idea to take a relative or friend with you. During the visit, you may meet members of the team who will be looking after you.

Tests before a stem cell transplant

You need different tests before treatment starts. Your doctor or specialist nurse will talk to you about the tests you need. Your tests may include:

  • blood tests to check your general health
  • blood tests to check for infections – such as hepatitis, HIV or cytomegalovirus (CMV)
  • chest x-ray to check your lungs and heart
  • breathing tests to check how well your lungs work
  • kidney tests to see how well your kidneys are working
  • heart tests such as an ECG (electrocardiogram) or ECHO (echocardiogram) to check your heart is healthy
  • a bone marrow biopsy to check if there are any cancer cells in the bone marrow
  • a pregnancy test.

Having a central or PICC line

If you do not have one already, you will have a central line or PICC line put in before the stem cell transplant. This is a thin, hollow tube that a doctor or nurse puts into a vein in your chest. It can be used to:

  • collect blood samples
  • give you chemotherapy and other drugs, such as antibiotics
  • give you the stem cells
  • give you fluids
  • give you blood and platelet transfusions.

Your blood count

Doctors measure the number of different blood cells with a blood test. They call this either a full blood count (FBC) or a blood count. Your blood count will be checked often during and after treatment. This is because the treatment will affect the levels of your blood cells.

The figures that show your blood cell levels look complicated when they are written down. But most people with cancer soon learn what they mean. For example, you may hear doctors or nurses saying things like ‘your haemoglobin is 135’ or ‘your neutrophils are 4’.

The figures below show the levels of different blood cells usually found in a healthy person.

Type of blood cell Levels
Red blood cells (Hb) 130 to 180g/l (men)

115 to 165g/l (women)
Platelets 150 to 400 x 109/l
White blood cells (WBC) 4.0 to 11.0 x 109/l
Neutrophils 2.0 to 7.5 x 109/l
Lymphocytes 1.5 to 4.5 x 109/l

These figures can be different from hospital to hospital. There may also be slight differences between people from different ethnic groups. Ask your doctor or nurse to explain more about your blood results if you are not sure.

About our information

  • References

    Below is a sample of the sources used in our stem cell and bone marrow transplants information. If you would like more information about the sources we use, please contact us at cancerinformationteam@macmillan.org.uk

    Carreras, Dunfour, Mohty and Kröger. The European Society for Blood and Bone Marrow Transplantation: Hematopoietic stem cell transplantation and cellular therapies. Springer, Switzerland. 2019. 

    FACT-JACIE International Standards for Hematopoietic Cellular Therapy – product collection, processing and administration. 7th edition. 2018. 

    Anthony Nolan. Operations and patient services user guide. Available from www.anthonynolan.org. Accessed January 2019.

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editor, Dr Anne Parker, Consultant Haematologist.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

The language we use

We want everyone affected by cancer to feel our information is written for them.

We try to make sure our information is as clear as possible. We use plain English, avoid jargon, explain any medical words, use illustrations to explain text, and make sure important points are highlighted clearly.

We use gender-inclusive language and talk to our readers as ‘you’ so that everyone feels included. Where clinically necessary we use the terms ‘men’ and ‘women’ or ‘male’ and ‘female’. For example, we do so when talking about parts of the body or mentioning statistics or research about who is affected. Our aims are for our information to be as clear and relevant as possible for everyone.

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