What Is Myelodysplastic Syndrome (MDS)? Understanding Symptoms, Types, and Treatment Options

Myelodysplastic syndrome (MDS) is a group of diverse bone marrow disorders characterized by the ineffective production of blood cells. Originating from abnormalities in hematopoietic stem cells, MDS leads to dysplastic (abnormally formed) blood cell development and a significantly increased risk of progression to acute myeloid leukemia (AML). This condition primarily affects the body's ability to maintain healthy levels of red blood cells, white blood cells, and platelets, resulting in chronic cytopenias—low blood counts across one or more cell lines.

Who Is Most at Risk for MDS?

The majority of MDS cases occur in older adults, with approximately 80% of diagnosed patients being over the age of 60. While it can develop in younger individuals, especially after exposure to chemotherapy, radiation, or certain environmental toxins, aging remains the most significant risk factor. Men are slightly more likely to develop MDS than women, and prior history of cancer treatment increases susceptibility.

Common Symptoms and Clinical Manifestations

Anemia is nearly universal among MDS patients, affecting almost all individuals diagnosed with the disorder. This deficiency in red blood cells often causes persistent fatigue, weakness, shortness of breath, and pale skin. Around 60% of patients experience neutropenia—low white blood cell counts—which compromises the immune system and makes them more vulnerable to recurrent infections.

In addition, between 40% and 60% of patients suffer from thrombocytopenia, or reduced platelet levels, increasing the risk of easy bruising, prolonged bleeding, and spontaneous hemorrhaging. These symptoms may develop gradually, often leading to delayed diagnosis as they are initially mistaken for signs of aging or other common conditions.

Classification: The Five Main Types of MDS

MDS is not a single disease but rather a spectrum of related disorders. According to the World Health Organization (WHO) classification, there are five primary subtypes:

Refractory Cytopenia with Unilineage Dysplasia (RCUD): Low counts in one blood cell type with visible dysplasia.
Refractory Anemia with Ring Sideroblasts (RARS): Anemia with abnormal iron accumulation in red blood cell precursors.
Refractory Cytopenia with Multilineage Dysplasia (RCMD): Involves two or more deficient blood cell lines.
Refractory Anemia with Excess Blasts (RAEB): Higher numbers of immature blast cells, divided into RAEB-1 and RAEB-2 based on blast percentage.
Myelodysplastic Syndrome, Unclassifiable (MDS-U): Cases that don't fit neatly into other categories.

Treatment Approaches and Management Strategies

Currently, there is no universally effective drug that cures MDS. However, treatment plans are tailored based on the patient's risk level, age, overall health, and genetic profile. The only potentially curative option available today is allogeneic hematopoietic stem cell transplantation (HSCT), which replaces diseased bone marrow with healthy donor stem cells. This procedure offers the best chance for long-term remission, particularly in younger, eligible patients.

Supportive and Disease-Modifying Therapies

For many patients, especially those who are not transplant candidates, management focuses on symptom relief and slowing disease progression. Common strategies include:

Growth factor support: Erythropoiesis-stimulating agents (ESAs) and granulocyte colony-stimulating factors (G-CSF) help boost red blood cell and white blood cell production.
Immunomodulatory drugs: Lenalidomide has shown efficacy, particularly in patients with a specific chromosomal abnormality (5q deletion).
Hypomethylating agents: Drugs like azacitidine and decitabine can reactivate silenced tumor-suppressor genes, improving blood counts and delaying transformation to AML.
Chemotherapy: Used in higher-risk cases, though response rates vary.
Blood transfusions: Regular red blood cell and platelet transfusions help manage severe anemia and bleeding risks.

Prognosis and Future Directions

The outlook for MDS varies widely—from indolent forms requiring minimal intervention to aggressive subtypes needing immediate treatment. Prognostic scoring systems like the Revised International Prognostic Scoring System (IPSS-R) help guide clinical decisions by assessing factors such as blast percentage, cytogenetic abnormalities, and degree of cytopenias.

Ongoing research continues to explore targeted therapies, gene editing, and novel immunotherapies that could transform how MDS is treated in the coming years. Early detection, personalized medicine, and multidisciplinary care remain key to improving quality of life and survival outcomes for patients living with this complex blood disorder.