Estimated Prevalence of MDS/MPN in the United States
The estimated prevalence of MDS/MPN (Myelodysplastic Syndromes/Myeloproliferative Neoplasms) in the United States is not precisely established in the available literature, but based on the known incidence of MDS alone (approximately 4 per 100,000 annually) and the fact that MDS/MPN represents a distinct but smaller subset of myeloid neoplasms, the prevalence is likely in the range of several thousand to low tens of thousands of patients. 1, 2
Understanding the MDS/MPN Category
MDS/MPN represents a distinct category of myeloid neoplasms that was formally added to the WHO classification in 2008, encompassing disorders with overlapping dysplastic and proliferative features. 1 This category includes:
- Chronic myelomonocytic leukemia (CMML) - the most common subtype
- Atypical chronic myeloid leukemia (aCML), BCR-ABL1 negative - a rare entity
- Juvenile myelomonocytic leukemia (JMML) - a rare childhood cancer
- MDS/MPN with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T)
- MDS/MPN, unclassifiable (MDS/MPN-U) 1
Epidemiological Context from MDS Data
While specific MDS/MPN prevalence data for the United States is not directly reported in the available evidence, we can extrapolate from MDS epidemiology:
- MDS incidence in the United States is approximately 3.4-4 per 100,000 people annually, translating to over 10,000 new diagnoses per year. 2, 3, 4, 5
- MDS prevalence is estimated at approximately 60,000 or more people living with the disease in the United States. 3, 4, 6
- The incidence increases dramatically with age, reaching 25-50 per 100,000 in individuals aged 65 years and older. 2, 1
MDS/MPN as a Subset
MDS/MPN disorders represent a smaller subset compared to classical MDS. The available evidence indicates:
- MDS/MPN-U remains an exceedingly rare disease entity with limited epidemiological data. 1
- In transplant registry data, only 86 MDS/MPN-NOS patients underwent transplant in Japan between 2001-2017, and 120 patients with MDS/MPN (including 48 NOS/U cases) underwent haploidentical transplantation in North America, suggesting the rarity of these conditions. 1
Clinical Implications
The lack of precise prevalence data for MDS/MPN in the United States reflects the rarity and diagnostic complexity of these conditions. 1 Key considerations include:
- MDS/MPN patients typically present in their seventh or eighth decades of life. 3, 4
- These disorders have a dismal prognosis, with median leukemia-free survival of 12-24 months for MDS/MPN-NOS, and worse outcomes (approaching 1 year) in some series. 1
- The progressive aging of the population is expected to increase the documented disease burden in the near future. 1, 6
Given the rarity of MDS/MPN and the absence of dedicated epidemiological studies using current diagnostic criteria, clinicians should recognize that these patients represent a small but clinically significant subset of myeloid neoplasms requiring specialized hematologic care and consideration for clinical trial enrollment. 1