A SMD ocorre principalmente em idosos; a idade média ao diagnóstico é 70-75 anos.[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
A SMD é mais comum nos homens do que nas mulheres (aproximadamente 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
Nos EUA, a incidência de SMD é de aproximadamente 4 por 100,000 (em todas as idades, com base em dados de 2018-2022), subindo para aproximadamente 41 por 100,000 em pessoas com ≥75 anos.[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
A incidência no Reino Unido e na Europa parece ser similar à dos EUA.[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
A SMD em adultos jovens e crianças é relativamente rara, e normalmente está associada a doenças congênitas (por exemplo, síndrome de Down, síndrome de Fanconi, síndrome de Bloom).[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
Nos países asiáticos, a média de idade em que os pacientes são diagnosticados é muito menor que em outros países.[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
Embora a razão para esta diferença não seja clara, a contaminação química e causas infecciosas em associação com diferenças étnicas podem contribuir.[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