Myelodysplastic Syndromes (MDS)

Myelodysplastic syndromes (MDS) are a group of bone marrow disorders in which the marrow makes blood cells that are abnormal in shape and function, and too few of them. MDS is sometimes called a "pre-leukemia" because in some patients it can progress to acute myeloid leukemia (AML).

Types of MDS

MDS is classified by how the cells look under the microscope, the number of blasts and the genetic changes present. Common types include:

• MDS with single-lineage dysplasia — one type of blood cell is affected
• MDS with multilineage dysplasia — two or more cell types are affected
• MDS with ring sideroblasts / SF3B1 mutation — iron builds up in developing red cells
• MDS with excess blasts — a higher-risk form with more immature cells
• MDS with isolated del(5q) — responds particularly well to lenalidomide

Causes and risk factors

• Age — most patients are over 65
• Previous chemotherapy or radiation therapy
• Exposure to benzene, tobacco smoke or certain industrial chemicals
• Some inherited bone marrow failure syndromes

Symptoms

• Tiredness, breathlessness and pale skin (anemia) — the most common problem
• Frequent infections from low white blood cells
• Easy bruising or bleeding from low platelets
• Many people are diagnosed after a routine blood test

Living with MDS

Lower-risk MDS can often be managed for many years with transfusions and medicines. Regular follow-up, infection prevention and a healthy diet help maintain quality of life.

Diagnosis confirms MDS, rules out other causes of low blood counts, and places the patient in a risk group that guides treatment.

Physical exam and health history

Your doctor asks about symptoms, past treatments, medicines and exposures, and examines you for signs of anemia, infection or bleeding.

Blood tests

• Complete blood count and blood smear
• Vitamin B12, folate, iron studies, thyroid and kidney tests to exclude other causes
• Erythropoietin (EPO) level, which helps predict response to growth-factor treatment

Bone marrow biopsy

Aspirate and biopsy show the abnormal (dysplastic) cells, the blast percentage and marrow cellularity. Cytogenetic and molecular tests (for example SF3B1, TP53, ASXL1) are performed on the sample.

Risk scoring

The IPSS-R and the newer IPSS-M combine blood counts, blast percentage, chromosome and gene changes to classify MDS from very low to very high risk. This score is the key to choosing treatment.

Lower-risk MDS treatment aims to improve blood counts and quality of life. Higher-risk MDS treatment aims to delay progression to leukemia and, where possible, cure the disease.

Supportive therapy

• Blood transfusion — red cell and platelet transfusions to treat anemia and bleeding
• Iron chelation — removes excess iron that builds up after many transfusions
• Erythropoiesis-stimulating agents — injections that help the marrow make red cells
• Luspatercept — improves anemia, especially in MDS with ring sideroblasts
• Antibiotics and growth factors — to prevent and treat infections

Disease-modifying treatment

• Lenalidomide — for MDS with del(5q)
• Hypomethylating agents — azacitidine or decitabine, the standard treatment for higher-risk MDS
• Immunosuppressive therapy — for selected patients with low-cellularity MDS
• Intensive chemotherapy — occasionally, before transplant

Bone marrow / stem cell transplant

An allogeneic stem cell transplant is currently the only treatment that can cure MDS. It is recommended for fit patients with higher-risk disease, using matched or haploidentical donors and reduced-intensity conditioning when appropriate.

Our hematologists and transplant physicians assess MDS risk and plan treatment together with each patient.