Stem Cell Transplant for Myelodysplastic Syndrome

A stem cell transplant (SCT) currently offers the only realistic chance to cure myelodysplastic syndrome (MDS), although many patients with MDS might not be eligible to have one. In this treatment, the patient receives high-dose chemotherapy and/or total body irradiation to kill the cells in the bone marrow (including the abnormal bone marrow cells). Then the patient gets new blood-forming stem cells.

There are 2 main types of SCT:

• For an allogeneic stem cell transplant, after the bone marrow is destroyed, the patient receives blood-forming stem cells from another person -- the donor. This is the type of transplant typically used for MDS. The results of this treatment tend to be best when the donor’s cell type (also known as the HLA type) is closely matched to the patient’s cell type and the donor is closely related to the patient, such as a brother or sister. Less often, the donor is matched to the patient, but is not related.
• In an autologous stem cell transplant, the patient gets back their own stem cells (which were removed before treatment). This type of transplant is not typically used for patients with MDS because the patient's bone marrow contains abnormal stem cells.

Allogeneic SCTs can have serious, even life-threatening, side effects, so they are typically done in younger patients who are in relatively good health. Patients in their 60s or even 70s have been transplanted successfully, but in older patients the SCT is generally done using less intensive (reduced intensity) chemotherapy and/or radiation. The lower doses may not kill all the bone marrow cells, but they are just enough to allow the donor cells to take hold and grow in the bone marrow. The lower doses also cause fewer side effects, which makes this type of transplant easier for older patients to tolerate. Still, some serious side effects are still possible.

Side effects

The early side effects from a SCT are similar to the side effects expected from chemotherapy and radiation, only more severe. One of the most serious side effects is low blood counts, which can lead to risks of serious infections and bleeding.

Another possible serious side effect from allogeneic transplants is graft-versus-host disease (GVHD). This occurs when the new immune cells (from the donor) see the patient’s tissues as foreign and attack them. GVHD can affect any part of the body and can be life threatening.

Although allogeneic SCT is currently the only treatment that can cure some people with MDS, not everyone who gets a transplant is cured. In addition, some people may die from complications of this treatment. Your chance for cure is higher if you are young and your MDS hasn’t begun to transform into leukemia. Still, doctors often recommend waiting until the MDS develops into a more advanced stage before considering a stem cell transplant.