MDS occurs primarily in older adults; median age at diagnosis is 70-75 years.[9]Sekeres MA, Taylor J. Diagnosis and treatment of myelodysplastic syndromes: a review. JAMA. 2022 Sep 6;328(9):872-80.
http://www.ncbi.nlm.nih.gov/pubmed/36066514?tool=bestpractice.com
[10]Roman E, Smith A, Appleton S, et al. Myeloid malignancies in the real-world: occurrence, progression and survival in the UK's population-based Haematological Malignancy Research Network 2004-15. Cancer Epidemiol. 2016 Jun;42:186-98.
https://www.sciencedirect.com/science/article/pii/S1877782116300364
http://www.ncbi.nlm.nih.gov/pubmed/27090942?tool=bestpractice.com
MDS is more common in males than in females (approximately 2:1).[10]Roman E, Smith A, Appleton S, et al. Myeloid malignancies in the real-world: occurrence, progression and survival in the UK's population-based Haematological Malignancy Research Network 2004-15. Cancer Epidemiol. 2016 Jun;42:186-98.
https://www.sciencedirect.com/science/article/pii/S1877782116300364
http://www.ncbi.nlm.nih.gov/pubmed/27090942?tool=bestpractice.com
[11]Killick SB, Wiseman DH, Quek L, et al. British Society for Haematology guidelines for the diagnosis and evaluation of prognosis of adult myelodysplastic syndromes. Br J Haematol. 2021 Jul;194(2):282-93.
https://onlinelibrary.wiley.com/doi/10.1111/bjh.17621
http://www.ncbi.nlm.nih.gov/pubmed/34137023?tool=bestpractice.com
[12]Killick SB, Ingram W, Culligan D, et al. British Society for Haematology guidelines for the management of adult myelodysplastic syndromes. Br J Haematol. 2021 Jul;194(2):267-81.
https://onlinelibrary.wiley.com/doi/10.1111/bjh.17612
http://www.ncbi.nlm.nih.gov/pubmed/34180045?tool=bestpractice.com
[13]National Institue of Health; National Cancer Institute. All cancer sites combined: recent trends in SEER age-adjusted incidence rates, 2000-2022. Jul 2025 [internet publication].
https://seer.cancer.gov/statistics-network/explorer
In the US, the incidence of MDS is approximately 4 per 100,000 (across all ages, based on 2018-2022 data), which rises to approximately 41 per 100,000 in those aged ≥75 years.[13]National Institue of Health; National Cancer Institute. All cancer sites combined: recent trends in SEER age-adjusted incidence rates, 2000-2022. Jul 2025 [internet publication].
https://seer.cancer.gov/statistics-network/explorer
Incidence in the UK and Europe appear to be similar to the US.[10]Roman E, Smith A, Appleton S, et al. Myeloid malignancies in the real-world: occurrence, progression and survival in the UK's population-based Haematological Malignancy Research Network 2004-15. Cancer Epidemiol. 2016 Jun;42:186-98.
https://www.sciencedirect.com/science/article/pii/S1877782116300364
http://www.ncbi.nlm.nih.gov/pubmed/27090942?tool=bestpractice.com
MDS in younger adults and children is relatively rare, and is often associated with congenital disorders (e.g., Down syndrome, Fanconi syndrome, Bloom syndrome).[14]National Comprehensive Cancer Network. NCCN clinical practice guidelines in oncology: myelodysplastic syndromes [internet publication].
https://www.nccn.org/guidelines/category_1
[15]Fenaux P, Haase D, Santini V, et al; ESMO Guidelines Committee. Myelodysplastic syndromes: ESMO clinical practice guidelines for diagnosis, treatment and follow-up. Ann Oncol. 2021 Feb;32(2):142-56.
https://www.annalsofoncology.org/article/S0923-7534(20)43129-1/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/33221366?tool=bestpractice.com
[16]Xavier AC, Kutny M, Costa LJ. Incidence and outcomes of paediatric myelodysplastic syndrome in the United States. Br J Haematol. 2018 Mar;180(6):898-901.
https://www.doi.org/10.1111/bjh.14460
http://www.ncbi.nlm.nih.gov/pubmed/28240841?tool=bestpractice.com
[17]Sperling AS, Gibson CJ, Ebert BL. The genetics of myelodysplastic syndrome: from clonal haematopoiesis to secondary leukaemia. Nat Rev Cancer. 2017 Jan;17(1):5-19.
http://www.ncbi.nlm.nih.gov/pubmed/27834397?tool=bestpractice.com
In Asian countries, the average age at which patients are diagnosed is much younger than in other countries.[15]Fenaux P, Haase D, Santini V, et al; ESMO Guidelines Committee. Myelodysplastic syndromes: ESMO clinical practice guidelines for diagnosis, treatment and follow-up. Ann Oncol. 2021 Feb;32(2):142-56.
https://www.annalsofoncology.org/article/S0923-7534(20)43129-1/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/33221366?tool=bestpractice.com
While the reason for this difference is unclear, chemical contamination and infectious causes in addition to ethnic differences may contribute.[18]Chen B, Zhao WL, Jin J, et al. Clinical and cytogenetic features of 508 Chinese patients with myelodysplastic syndrome and comparison with those in Western countries. Leukemia. 2005 May;19(5):767-75.
http://www.ncbi.nlm.nih.gov/pubmed/15759035?tool=bestpractice.com