Bone marrow and stem cell transplants for chronic myeloid leukaemia (CML)

Intensive treatment means high dose chemotherapy. You may also have radiotherapy to your whole body as part of your intensive treatment. The aim of the treatment is to try to cure your chronic leukaemia, or control it for longer. As well as destroying the leukaemia cells, the treatment destroys your bone marrow cells. The bone marrow is the spongy substance inside your bones. It contains cells called stem cells, which make all your blood cells. After high dose chemotherapy your bone marrow cells need to be replaced (transplanted), as it is vital you have a functioning bone marrow to survive. Your bone marrow cells are replaced with someone else's bone marrow or stem cells. This is called an allogeneic transplant. 

You have the donor bone marrow or stem cells through a drip (transfusion), into a vein. The cells find their way to the centre of your bones and begin to make blood cells after a few days or weeks.

The first choice of treatment for CML these days is usually the biological therapy imatinib (Glivec). But your doctor may suggest intensive treatment if you 

• Have been treated with tyrosine kinase inhibitors but have not responded 
• Are very young
• Have a suitable match for a transplant

Your age and general level of fitness is an important consideration when deciding whether this type of treatment is suitable for you. This is because it is very intensive treatment and there is a risk that you may not survive it. Generally, you have to be younger than 65 years old, but some people who are very fit and healthy may be able to have it.

Of all the chronic leukaemias, doctors use intensive treatment most often for chronic myeloid leukaemia. At the moment, the only known cure for CML for some people is a donor bone marrow or stem cell transplant.

The bone marrow contains the stem cells. So the result of intensive treatment is the same whether you have a stem cell or bone marrow transplant. The main differences are

• Your donor needs an anaesthetic to have bone marrow collected
• Stem cell collection takes longer – your donor will have treatment over a couple of weeks and each time the collection takes up to 4 hours
• Your healthy donor has to have growth factor injections to get the stem cells out into the bloodstream for collection
• Your blood counts may recover more quickly after stem cell transplant

There may be a choice about whether you have bone marrow or stem cells. Your doctor may prefer one type of treatment to the other. You need to discuss this with your doctor. The choice is too individual for us to give general information here.

Doctors call this allogeneic transplant (pronounced allo-gen-ay-ic). The donor's cells have to match your own. The most suitable donor is usually a close relative, such as a brother or sister. There is a 1 in 4 chance of a brother or sister being a good match.

It is sometimes possible to get a match from a donor who is not a relative. If you need this treatment, your doctor will approach the Anthony Nolan Bone Marrow Register to find a matched unrelated donor (MUD).

To make sure that your donor's cells match your own, you will both have blood tests to see how many of the proteins on the surface of the blood cells are the same. This is called tissue typing or HLA matching. HLA stands for human leucocyte antigen. Once you have a donor, he or she will be asked to come to the hospital and give marrow or have stem cells collected. The collection (harvest) will be timed for after your high dose chemotherapy, and possibly radiotherapy, have finished. This is so that you can have the donor infusion as soon after the collection as possible. There is more about bone marrow and stem cell transplants in the cancer treatment section of CancerHelp UK.

This is sometimes called a bone marrow harvest. It means your donor has a minor operation under general anaesthetic.

To remove the marrow, the doctor puts a needle through the skin into the hipbone. The doctor then uses a large syringe to suck out the marrow. About 2 pints of marrow are needed. To get enough, the doctor usually has to put the needle into several different parts of the pelvis. Occasionally, the doctor uses the chest bone (sternum) as well.

When the donor wakes up, there will be up to 6 needle puncture sites. Usually they will feel a bit bruised and paracetamol may be needed for a few days. The donor usually has to stay in hospital overnight after a bone marrow harvest. This is to make sure they have recovered from the anaesthetic. They may also need a blood transfusion.

There is more about harvesting marrow in the bone marrow and stem cell transplant section of CancerHelp UK.

Stem cells are very early blood cells. They are normally found in the bone marrow. Doctors use growth factor injections to get them into the bloodstream. This makes it easier to collect them. Doctors call stem cell collection leukapharesis (pronounced loo-ka-far-ee-sis).

Before a stem cell collection, you will have regular blood tests. When your blood count is high enough, you have the stem cell collection.

Collecting stem cells takes 3 or 4 hours. You lie down on a couch and have a fine tube put into a vein in each of your arms. The nurse attaches these to a machine called a stem cell separator. Your blood will pass out of one drip, through the machine and back into your body through the other drip. The machine filters the stem cells out of your blood, but gives you the rest of the cells and the plasma back.

The stem cells are frozen and stored until after your high dose chemotherapy and radiotherapy (if you have this).

Stem cell transplants are similar to bone marrow transplants but your blood count recovers more quickly. This means the time that you are at risk of infection is shorter than with a bone marrow transplant. There is more about the process of stem cell transplant in the cancer treatment section of CancerHelp UK.

If you are donating stem cells, you may need to have growth factors as an injection, just under the skin. These will usually be in your tummy (abdomen), or into an arm or a leg. You usually have injections once a day, for up to 10 days at a time. The injections are not difficult to do. If you don't need to be in hospital, you can learn to give them yourself at home. If you don't feel able to do the injections yourself, someone in your family may be able to give them to you. Or a district nurse can come into your home and give them. After your course of injections, you will have regular blood tests to see how your blood counts are doing. When they are high enough, you will have the stem cells collected from your blood.

Growth factor injections don't have many side effects. Some people have itching around the injection site. You may have some aching in your bones after you have had a few injections. This is because there are a lot of blood cells being made inside the bones. The aching is usually easy to control with a mild painkiller, such as paracetamol. The pain will go away on its own after a day or so.

Doctors are investigating a new type of transplant that they hope will have less severe side effects. It is called a reduced intensity conditioning transplant (RIC) or a mini transplant. You have lower doses of chemotherapy, so the side effects are not as bad. This treatment may not kill all your bone marrow cells. If it doesn't, you have more infusions from your donor after your transplant. This is called donor lymphocyte infusion. There is more about mini transplant in the page on CML research.

There is general information about bone marrow and stem cell transplants in the cancer treatment section of CancerHelp UK, including detailed information about the side effects. You can also get more information and support from one of the chronic leukaemia organisations. They will be happy to help you. They often have fact sheets and booklets they can send.