MDS, or Myelodysplastic Syndrome is a malfunction of the Bone Marrow. The Bone Marrow is the factory where normal blood cell production takes place in an orderly fashion. Blood cells include White Blood Cells (WBCs), Red Blood Cells (RBCs) and Platelets. These start as stem cells, and pass through a stepwise, orderly maturation process to the final product. MDS produces a varying degree of malfunction, resulting in low blood count numbers. The cause of MDS is unknown, but in rare circumstances, the bone marrow is damaged by previous chemotherapy. The malfunction often shows up 5 years later, as has been the case in a well-known TV newsperson. She was treated for breast Cancer, and 5 years later, is now battling MDS.
Most often, MDS is asymptomatic for a long time. It is detected due to an annual blood test showing low counts. It can cause
- Low-grade anemia, causing no symptoms initially, then some fatigue and decreased exercise tolerance, then an increasing requirement for blood transfusions. This anemia is not caused by lack of Iron or B12, but rather a malfunction of the production process.
- Low white count, which may cause repeated infections
- Low platelet count, causing bruising or bleeding complications
- Evolution into more aggressive forms can occur over time, including Acute Myeloid Leukemia
Diagnosis: It is often incidentally discovered, on a routine CBC. It then requires a Bone Marrow Biopsy in which a sample of marrow is extracted with a needle inserted through the skin into the bone, usually the pelvic crest in the small of the back. The marrow is also tested for some genetic mutations, which can guide therapy, and predict for response.
An International Prognostic Scoring System (IPSS) score is assigned, since the progression of the disease can be quite varied. This groups patients into low, intermediate and high-risk groups. Besides the IPSS score, treatment is chosen based on the age and performance status.
Treatment:
The Low Risk group may not require any intervention other than occasional blood transfusion.
The Intermediate and High Risk groups will need more intervention with chemotherapy, which can improve transfusion requirements, slow disease progression, improve quality of life, and possibly extend life. Current chemotherapy drugs include 5-Azacytadine or Decitabine, given intravenously, at regular intervals. Compared to supportive care alone, there is benefit to chemotherapy.
Acute Myeloid Leukemia will require full, high dose chemotherapy like an acute leukemia. The outcome is more guarded than AML which does not evolve from MDS.
Bone Marrow transplants are considered in younger (<60 years) patients with aggressive disease and a donor match. It is the only treatment, which carries any possibility of recreating a normal marrow.
Supportive Care:
-Erythropoietin injections can sometimes push the bone marrow to work a little harder to raise RBC production. Although the body is producing native Erythropoietin, booster shots every 1-3 weeks may help.
-G-CSF injections to raise the WBCs, but this is not common, unless there are repeated infections.
-Platelet transfusions if there is bleeding, or for procedures. At the moment, platelet production boosting injections are not being used for MDS.