Myelodysplastic Syndromes (MDS)

Myelodysplastic syndromes (MDS) are a group of bone marrow disorders in which the marrow fails to produce sufficient healthy blood cells. These conditions arise from mutations in hematopoietic stem cells, leading to ineffective blood formation and the accumulation of immature or abnormal cells. As a result, patients may experience anemia, infections, and bleeding. Although the exact cause of these mutations is often unknown, MDS has been linked to advanced age, genetic predisposition, environmental exposures, and prior chemotherapy or radiation therapy. MDS is considered rare, with an estimated incidence of 4 per 100,000 people annually, though rates are significantly higher in individuals over 60. In some cases, MDS can progress to acute myeloid leukemia (AML). Types of Myelodysplastic Syndromes MDS is classified based on the number of affected blood cell lines, the presence of abnormal cells, and genetic findings: MDS with Single Lineage Dysplasia (MDS-SLD): One blood cell type is dysplastic, usually associated with cytopenia. MDS with Multilineage Dysplasia (MDS-MLD): Two or more blood cell lines are affected, often causing more severe symptoms. MDS with Ring Sideroblasts (MDS-RS): MDS-RS-SLD – ring sideroblasts with single lineage dysplasia MDS-RS-MLD – ring sideroblasts with multilineage dysplasia MDS with Excess Blasts (MDS-EB): MDS-EB1 – 5–9% blasts in blood or 5–10% in marrow MDS-EB2 – 10–19% blasts in blood or 10–20% in marrow MDS with isolated del(5q): Characterized by a chromosome 5 deletion, typically with anemia and normal or elevated platelets. MDS, Unclassifiable (MDS-U): Does not meet criteria for other categories. Each subtype carries a variable risk of progression to AML. Causes and Risk Factors Key risk factors include: Age (most cases occur after 60) Environmental exposures (benzene, pesticides, tobacco smoke) Prior cancer therapy (therapy-related MDS) Inherited bone marrow failure syndromes Rare familial genetic predisposition Lifestyle factors such as smoking and alcohol use Symptoms of MDS Symptoms reflect low or dysfunctional blood cell production: Anemia: fatigue, weakness, shortness of breath, pallor Leukopenia / neutropenia: recurrent or severe infections Thrombocytopenia: easy bruising, bleeding, prolonged clotting Severity ranges from mild to life-threatening and significantly impacts quality of life. Diagnosis Diagnosis requires a comprehensive hematologic evaluation: Complete blood count (CBC) Peripheral blood smear Bone marrow aspiration and biopsy Cytogenetic and molecular genetic testing Flow cytometry for cellular characterization These tests allow accurate classification, prognostication, and treatment planning. Treatment Options Treatment is personalized based on MDS risk level, age, health status, and goals of care. Lower-Risk MDS Supportive care (blood and platelet transfusions) Erythropoiesis-stimulating agents (ESAs) Iron chelation therapy Immunosuppressive therapy in selected cases Higher-Risk MDS Hypomethylating agents (azacitidine, decitabine) Chemotherapy Allogeneic stem cell transplantation (the only curative option) Participation in clinical trials Living with MDS Managing MDS involves addressing both physical and emotional challenges. Regular follow-up, symptom control, nutritional support, and psychological care are essential. Palliative and supportive services play a key role in maintaining quality of life. Expert Care at Sheba Medical Center The Hemato-Oncology Department at Sheba Medical Center specializes in the diagnosis and treatment of myelodysplastic syndromes, offering advanced molecular diagnostics, personalized therapies, and access to innovative clinical trials. Sheba’s multidisciplinary team is committed to delivering state-of-the-art care with compassion, recognizing that every MDS journey is unique.