Red cell and platelet transfusions are helpful in relieving the symptoms of Myelodysplastic Syndrome (MDS). While they do necessitate frequent visits to the hospital outpatient clinic, transfusions remain a cornerstone therapy in MDS.
Intravenous chemotherapy, although effective in patients with frank acute leukemia, is much less effective in MDS. Less than 50% of MDS patients achieve remission with this type of chemotherapy. In patients who do enter a remission, the MDS always recurs, often very quickly after completion of treatment. Furthermore, neither duration of survival nor quality of life is improved in patients responding to chemotherapy. As a result, except in extraordinary circumstances, this type of chemotherapy is not offered to patients with MDS in Vancouver.
High-dose chemotherapy, with or without radiation followed by a related or unrelated donor blood and marrow transplant (BMT) is the only curative therapy available for patients with MDS. In Vancouver, 30% of MDS patients have been cured by this procedure although the results have not been as good for those patients with certain chromosomal abnormalities in their bone marrow cells. These include changes involving chromosome 7 or when multiple changes are present.
In general, while a BMT is recommended for all eligible patients with MDS, the results have not been as favourable as those seen in patients with acute leukemia. This is due to both a higher relapse rate despite the transplant and a higher complication rate with the procedure.
Reduced Intensity Conditioning (RIC) Transplant
This new procedure allows stem cell transplants to be performed more safely in older, less fit patients. Conditioning chemotherapy is milder and is designed only to suppress the patient's immune system enough to accept the donor's cells.
The risk of a RIC-transplant is still significant and it is not yet clear whether this procedure can cure patients with MDS.
This is a chemotherapy drug, which has been shown (in a good study) to prolong survival and to improve quality of life in MDS patients. This drug, only available through the Health Protection Branch in Canada, is given by injection for seven days each month. It can decrease the likelihood of infection or the need for a transfusion.
Thalidomide
While not formally funded for patients with MDS, thalidomide can reduce the red cell transfusion needs in 30% of patients with early MDS. It is expensive and causes drowsiness and constipation as common side effects.
ATG
Anti-thymocyte globulin (ATG) has been used successfully in some patients with early MDS, especially if the bone marrow is under active or aplastic. It can produce numerous infusional side effects, these include; fever, chills, skin rash, shortness of breath, joint pain, but, of greater concern, it can predispose to serious and unusual infections.
