Catholic University Catholic Hematology Hospital

Allogeneic hematopoietic stem cell transplantation is a complex but potentially curative treatment for myelodysplastic syndrome (MDS). It involves intensive treatment with chemotherapy and sometimes radiation to destroy the diseased bone marrow, followed by a transplant of healthy donor stem cells to reestablish normal bone marrow function.

This approach is generally considered for younger patients or those with a high-risk form of MDS. However, the development of reduced-intensity conditioning regimens has made it possible for older patients or those with other health issues to undergo transplantation. For those at high risk, transplantation is recommended soon after diagnosis, while for those at lower risk, it may be deferred until other treatments have been tried or the disease begins to progress.

Finding a matched donor usually starts with the patient's siblings, but if no sibling match is found, other options include unrelated donors with full or partial HLA matches or even haploidentical family members. Fortunately, the outcomes between different types of donors are becoming increasingly comparable. Though bone marrow has traditionally been the source of stem cells for transplantation, the use of peripheral blood stem cells has become more common. This method has several benefits, including faster recovery of bone marrow function, potentially lower relapse rates, and possibly better overall disease-free survival when compared to bone marrow transplants.

The prognosis after allogeneic hematopoietic stem cell transplantation for Myelodysplastic Syndrome (MDS) is influenced heavily by the patient's age at the time of the procedure and the risk category of their disease. Clinical trials from the early 2000s indicate that patients under 50, with a low-risk disease profile, and who received a transplant from a fully matched sibling donor, often saw long-term survival rates above 50%. For those with high-risk MDS, the long-term survival was around 30-40%.

At the Catholic Hematology Hospital, the 5-year survival rate following allogeneic hematopoietic stem cell transplantation in patients with low-risk MDS has been over 60%. For patients with high-risk MDS, the survival rate falls to below 40%.

If the disease relapses after transplantation, treatment options may include hypomethylating agents like Vidaza or Dacogen, donor lymphocyte infusion, or a possible second stem cell transplantation. The choice of treatment greatly depends on the patient's condition and overall health. Ongoing research aims to enhance the effectiveness of stem cell transplantation for MDS. Efforts are focused on developing maintenance therapies post-transplant, preemptive treatments for any remaining disease, and improved management of graft-versus-host disease. These areas of research hold promise for significant improvements in MDS treatment outcomes in the foreseeable future.