What is Myelodysplastic Syndrome (MDS)?

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Last updated: April 22, 2025View editorial policy

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From the Guidelines

Myelodysplastic syndromes (MDS) are a group of myeloid clonal hematopathies with a heterogeneous spectrum of presentation, characterized by ineffective production of blood cells in the bone marrow, leading to cytopenia-associated complications and a potential risk of evolving into acute myeloid leukemia (AML) 1. The diagnosis and disease stratification of MDS are based on multiple factors, including clinical data, peripheral blood and bone marrow morphology, fluorescence in situ hybridization, cytogenetics, flow cytometry, and next-generation sequencing myeloid mutation panels 1. Key characteristics of MDS include:

  • A relatively high incidence in older adults, with approximately 4.5 cases per 100,000 people per year in the general population 1
  • A rare occurrence in children, adolescents, and young adults, with an incidence of 0.1 per 100,000 people per year in individuals aged <40 years 1
  • An increased risk of progression to AML, with lower response rates to standard therapy compared to de novo AML 1
  • The presence of nonhematologic comorbidities and the relative inability of older patients to tolerate intensive forms of therapy, complicating the management of MDS 1 The management of MDS is complex and requires a comprehensive approach, taking into account the patient's age, comorbidities, and disease severity, with treatment options including supportive care, growth factors, immunosuppressive therapy, hypomethylating agents, and stem cell transplantation 1.

From the FDA Drug Label

14 CLINICAL STUDIES 14.1 Myelodysplastic Syndromes (MDS)

Study 1 was a randomized, open-label, controlled trial carried out in 53 U. S sites compared the safety and efficacy of subcutaneous azacitidine for injection plus supportive care with supportive care alone (“observation”) in adult patients with any of the five FAB subtypes of myelodysplastic syndromes (MDS): refractory anemia (RA), RA with ringed sideroblasts (RARS), RA with excess blasts (RAEB), RAEB in transformation (RAEB-T), and chronic myelomonocytic leukemia (CMMoL)

Myelodysplastic Syndromes (MDS) are a group of disorders characterized by the following subtypes:

  • Refractory anemia (RA)
  • RA with ringed sideroblasts (RARS)
  • RA with excess blasts (RAEB)
  • RAEB in transformation (RAEB-T)
  • Chronic myelomonocytic leukemia (CMMoL) 2

From the Research

Definition of MDS

  • Myelodysplastic syndromes (MDS) are a group of clonal hematopoietic malignancies characterized by morphologic bone marrow dysplasia, anemia, neutropenia, or thrombocytopenia 3
  • MDS are associated with an increased risk of acute myeloid leukemia (AML) 3, 4, 5
  • MDS are a heterogeneous group of myeloid disorders characterized by peripheral blood cytopenias and increased risk of transformation to AML 4

Characteristics of MDS

  • MDS are characterized by reduced numbers of peripheral blood cells, an increased risk of AML transformation, and reduced survival 3
  • The median age at diagnosis is approximately 70 years, and the yearly incidence rate increases to 25 per 100 000 in people aged 65 years and older 3
  • Risk factors associated with MDS include older age and prior exposures to toxins such as chemotherapy or radiation therapy 3, 5
  • MDS are more common in men compared with women (with yearly incidence rates of approximately 5.4 vs 2.9 per 100 000) 3

Diagnosis and Treatment of MDS

  • Diagnosis of MDS is based on morphological evidence of dysplasia upon visual examination of a bone marrow aspirate and biopsy 4
  • Prognosis of patients with MDS can be calculated using a number of scoring systems, including the International Prognostic Scoring System (IPSS) 4
  • Therapy for MDS is selected based on risk, transfusion needs, percent of bone marrow blasts, and cytogenetic and mutational profiles 4, 6, 7
  • Treatments for MDS include growth factor support, lenalidomide, hypomethylating agents (such as azacitidine and decitabine), intensive chemotherapy, and allogeneic stem cell transplantation 4, 6, 7

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Myelodysplastic syndromes.

International journal of hematology, 1997

Research

Decitabine in the treatment of myelodysplastic syndromes.

Expert review of anticancer therapy, 2010

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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