Myelodysplastic Syndromes

Myelodysplastic syndromes (MDS) are a heterogenous group of chronic hematological malignancies. The condition is characterised by dysplasia and ineffective hematopoeisis, and there is a risk of progression to acute myeloid leukemia in these patients. There are an increasing number of cancer genes carrying recurrent somatic mutations in MDS such as JAK2, KRAS and CBL. Apart from genetic mutations, MDS can occur after exposure to alkylating agents and radiation. Disease onset before 50 years is rare and it appears to have a higher incidence in the male population. Patients usually present with anaemia and or other cytopenias.

Disease prognosis is scored via the International Prognostic Scoring System (IPSS) where risk is based on the percentage of myeloblasts in the bone marrow, cytogenetic findings and number of cell lines affected by cytopenia. Allogeneic hematopoietic stem cell transplantation can result in long-term remission in patients. However, it is not suitable for the majority of patients as most patients are around 70 years of age. Demethylating agents and lenalidomide have had positive effects on response and remission rates.