Stem cell transplant for myelodysplastic syndrome

A stem cell transplant (SCT) is the only treatment that can cure myelodysplastic syndrome (MDS). In this treatment, the patient gets very strong chemotherapy (chemo) and perhaps radiation to kill cells in the bone marrow. Once the bone marrow cells are destroyed, the patient gets new, healthy, blood-forming stem cells. For patients with MDS, these new stem cells come from a donor -- often a brother or sister. This is called an allogeneic stem cell transplant. If there is no matching family member to be a donor, sometimes a matched, unrelated donor may be used. Using stem cells from an unrelated donor has more risks than using stem cells from a relative.

How the process works

Most often, stem cells are taken from the donor’s blood in a process called apheresis. The stem cells are frozen and stored. The patient then gets high-dose chemo and, often, radiation treatment. This destroys the MDS cells, but it also kills the normal cells in the bone marrow.

The donor’s stem cells are then given to the patient as a transfusion. These cells travel through the blood to the bone marrow where they settle and start to grow. Over time they start making white blood cells, then platelets and, finally, red blood cells.

There is a newer type of transplant, called a mini-transplant (or a non-myeloablative allogeneic stem cell transplant) that can be used. It differs from the standard approach in that low doses of chemo or radiation are used. This makes it easier on patients who are older. Side effects, though, are still a major problem with this low-dose method.

Side effects

Transplant can have serious, even fatal, side effects and is rarely used in older patients. Because of the side effects, many doctors only use SCT in people younger than a certain age.

The side effects of SCT can be divided into early and long-term effects. Early on, the side effects are much the same as those caused by high-dose chemo. The side effects that occur later can last for a long time. They include:

• Radiation damage to the lungs (this is rare)
• Damage to the ovaries that can result in infertility, sudden change of life (menopause), and hot flashes
• Damage to the thyroid gland
• Cataracts (clouding of the eye that can cause vision problems)

The most serious side effect from allogeneic transplant is called graft-versus-host disease (or GVHD). This happens when the new immune cells (from the donor) see the patient's tissues as foreign and so attack them. GVHD can happen early on or it can start later. Symptoms include weakness, tiredness, dry mouth, rashes, infection, diarrhea (which can be severe), and muscle aches. Severe GVHD can even be fatal. Drugs to suppress the immune system are given as part of the transplant to prevent or treat GVHD.

Right now allogeneic SCT is the only treatment that can cure some patients with MDS, but not all patients who get a transplant are cured. Also, patients may die from complications of this treatment. Your chance for cure is higher if you are young and your MDS hasn’t begun to change into leukemia. Still, doctors recommend waiting until the MDS is in a more advanced stage before thinking about a transplant.

If you would like more detailed information on SCT, please see our document Stem Cell Transplant (Peripheral Blood, Bone Marrow, and Cord Blood Transplants). You can read it on our Web site or get a copy by calling 1-800-227-2345.