Maria Arini Lopez, PT, DPT, CSCS, CMTPT, CIMT is a freelance medical writer and Doctor of Physical Therapy from Maryland. She has expertise in the therapeutic areas of orthopedics, neurology, chronic pain, gastrointestinal dysfunctions, and rare diseases especially Ehlers Danlos Syndrome.
Myelodysplastic syndromes (MDS) are a heterogenous group of rare hematological neoplasms affecting the production of normal blood cells in the bone marrow. Damage to the DNA of hematopoietic stem cells results in the synthesis of abnormal red cells, white cells, and/or platelets that do not mature or function properly.1
Incidence and Prevalence of MDS
The annual incidence of MDS in the United States is estimated to be approximately 4.9 cases per 100,000 persons, according to the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) Program database from 2007 through 2011.2
More recent estimates indicate that the incidence of MDS is increasing, possibly as a consequence of the growing number of older individuals.3 Estimates of the incidence of MDS vary widely, ranging between 10,000 and 55,000 new cases per year.3-5 The incidence of MDS in Europe is projected to be double that in the United States.5
On the basis of the estimated annual incidence and median survival rates for MDS, the projected prevalence of MDS in the United States is between 60,000 and 120,000.5
A systematic review of the global incidence and prevalence of MDS published in 2016 analyzed data from 25 studies reporting MDS incidence and 2 reporting MDS prevalence. The global incidence of MDS ranged between 0.06 and 0.26 per 100,000. The global prevalence of MDS ranged from 0.22 to 13.2 per 100,000 for all age categories, genders, and ethnicities.6 Orphanet similarly reports a global prevalence of MDS of between 1 and 9 per 100,000.7
Read more about MDS diagnosis
Race/Ethnicity Factors of MDS
Several sources indicate that MDS occurs more frequently in White individuals than in other ethnic groups.2,8-10
Epidemiologists in a study conducted at Montefiore Medical Center from 1997 to 2011 reported a greater prevalence of thrombocytopenia in Hispanic individuals with MDS in comparison with other ethnic groups; however, it was not significant.8 Median survival times were higher in Hispanic individuals and Black individuals (8.6 years and 6.2 years, respectively) than in White individuals (3.7 years).8
In a 2022 epidemiological study, researchers reported that overall survival rates were higher in individuals of African descent than in those of European or Hispanic descent.10
The epidemiology of MDS is distinct in Japan and Eastern Europe, including an increased risk in survivors of the 1945 Hiroshima and Nagasaki atomic bomb explosions that is lasting into the 21st century.5
In China and South Asia, there is a higher incidence of patients with more complex karyotypes and monosomy 7. In the same regions, there is less incidence of some MDS subtypes, such as refractory anemia with ring sideroblasts, than in the West. The reason is unknown but may have to do with genetics or environment.5
Read more about MDS etiology
Age Factors of MDS
The incidence of MDS increases with age.2-4,11,12 The onset of MDS is usually in individuals older than 65 years. The onset is most frequent in people older than 80 years.2
Disease onset before age 50 years is atypical unless it is treatment-related. The median age at the presentation of MDS is 70 years.4,11
However, a 2005 retrospective comparative study found that Chinese patients with MDS were diagnosed at younger ages, with a median of 49 years vs 65 to 73 years in Western countries.5
Read more about MDS risk factors
Sex Factors of MDS
Many sources indicate that most subtypes of MDS occur more often in men than in women.2,3,11,12 The exception is the MDS subtype with isolated 5q deletion, which is more common in women.11
Read more about MDS genetics
Impact of Subtype on MDS
SEER incidence studies indicate the following epidemiology for the various MDS subtypes:
Myelodysplastic Syndrome with Multilineage Dysplasia
This subtype has a median age at onset of 70 years in adults, with a slight male predominance. It occurs in all age groups and is the most common MDS subtype in children; however, no gender predominance is seen in children. This subtype accounts for approximately 30% of all MDS cases. Median survival is approximately 30 months, with approximately 50% mortality within 2 years.13
Myelodysplastic Syndrome with Single Lineage Dysplasia
This subtype has a median age at onset of between 65 and 70 years without any gender predominance. It accounts for between 10% and 20% of all MDS cases. Median survival ranges between 69 and 108 months.14
Myelodysplastic Syndrome with Isolated Deletion 5q
This subtype has a median age at onset of approximately 67 years and occurs more frequently in women. Individuals with this MDS subtype have a median survival of 145 months.15
Myelodysplastic Syndrome with Excess Blasts
This subtype occurs in individuals older than 50 years without gender predominance. It accounts for approximately 40% of all MDS cases. Median survival times are approximately 16 months for individuals who have refractory anemia with excess blasts (RAEB) type 1 and between 3 and 12 months for individuals with RAEB type 2.16
Myelodysplastic Syndrome with Ring Sideroblasts and Single Lineage Dysplasia
This subtype has a median age at onset between 60 and 73 years without gender predominance. It accounts for between 3% and 11% of all MDS cases. Median survival ranges between 69 and 108 months.17
Myelodysplastic Syndrome with Ring Sideroblasts and Multilineage Dysplasia
This subtype has a median age at onset between 60 and 73 years. It accounts for approximately 13% of all MDS cases. Median survival is approximately 28 months.18
Myelodysplastic Syndrome, Unclassifiable
This subtype does not have any relevant epidemiological data according to SEER. 19 This MDS subtype has been removed from the 2022 World Health Organization classification system for myelodysplastic neoplasms.20 Some cases of unclassifiable MDS may be hypoplastic MDS, which accounts for approximately 10% of MDS cases.19
Read more about MDS types
- Myelodysplastic syndrome. MedlinePlus. Accessed June 10, 2023.
- Dotson JL, Lebowicz Y. Myelodysplastic syndrome StatPearls [Internet]. Updated July 18, 2022. Accessed June 10, 2023.
- Besa EC. Myelodysplastic syndrome (MDS): epidemiology. Medscape. Updated October 1, 2022. Accessed June 10, 2023.
- Key statistics for myelodysplastic syndromes. American Cancer Society. Accessed June 10, 2023.
- Bejar R, Steensma DP. Recent developments in myelodysplastic syndromes. Blood. 2014;124(18):2793-2803. doi:10.1182/blood-2014-04-522136
- Lubeck DP, Danese M, Jennifer D, Miller K, Richhariya A, Garfin PM. Systematic literature review of the global incidence and prevalence of myelodysplastic syndrome and acute myeloid leukemia. Blood. 2016;128(22):5930. doi:10.1182/blood.V128.22.5930.5930
- Myelodysplastic syndrome. Orphanet. Accessed June 10, 2023.
- Sridharan A, Jain R, Bachhuber MA, et al. Epidemiologic study of myelodysplastic syndromes in a multiethnic, inner city cohort. Exp Hematol Oncol. 2014;3:22. doi:10.1186/2162-3619-3-22
- Rollison DE, Howlader N, Smith MT, et al. Epidemiology of myelodysplastic syndromes and chronic myeloproliferative disorders in the United States, 2001-2004, using data from the NAACCR and SEER programs. Blood. 2008;112(1):45-52. doi:10.1182/blood-2008-01-134858
- Goksu SY, Ozer M, Goksu BB, et al. The impact of race and ethnicity on outcomes of patients with myelodysplastic syndromes: a population-based analysis. Leuk Lymphoma. 2022;63(7):1651-1659. doi:10.1080/10428194.2022.2032034
- Aster JC, Stone RM. Clinical manifestations, diagnosis, and classification of myelodysplastic syndromes (MDS). UpToDate. Accessed June 10, 2023.
- Neukirchen J, Schoonen WM, Strupp C, et al. Incidence and prevalence of myelodysplastic syndromes: data from the Düsseldorf MDS-registry. Leuk Res. 2011;35(12):1591-1596. doi:10.1016/j.leukres.2011.06.001
- Myelodysplastic syndrome with multilineage dysplasia. National Cancer Institute SEER Program. Accessed June 10, 2023.
- Myelodysplastic syndrome with single lineage dysplasia. National Cancer Institute SEER Program. Accessed June 10, 2023.
- Myelodysplastic syndrome with isolated del(5q). National Cancer Institute SEER Program. Accessed June 10, 2023.
- Myelodysplastic syndrome with excess blasts. National Cancer Institute SEER program. Accessed June 10, 2023.
- Myelodysplastic syndrome with ring sideroblasts and single lineage dysplasia. National Cancer Institute SEER Program. Accessed June 10, 2023.
- Myelodysplastic syndrome with ring sideroblasts and multilineage dysplasia. National Cancer Institute SEER Program. Accessed June 10, 2023.
- Myelodysplastic syndrome, unclassifiable. National Cancer Institute SEER Program. Accessed June 10, 2023.
- Zhang Y, Wu J, Qin T, et al. Comparison of the revised 4th (2016) and 5th (2022) editions of the World Health Organization classification of myelodysplastic neoplasms. Leukemia. 2022;36(12):2875-2882. doi:10.1038/s41375-022-01718-7
Reviewed by Hasan Avcu, MD, on 6/12/2023.