Prognosis

The natural course of MDS is very variable, depending on several factors, including cytogenetics and severity of cytopenia. Patients categorised by the revised IPSS-R system as very high-risk have a median overall survival rate of 0.8 years compared with those in the very low- risk category who have a median overall survival rate of 8.8 years. (1)

Death results from bleeding, infection, transformation to AML, or transfusion related iron-overload. Remission occurs in less than half of cases and typically, is short lived.

Risks of leukaemic transformation are:

• 5-10% in refractory anaemia and in refractory anaemia with ringed sideroblasts
• 40-50% in refractory anaemia with excess blasts
• 100% in refractory anaemia with excess blasts in transformation

Median survival figures after diagnosis are:

• 3-5 years in refractory anaemia and in refractory anaemia with ringed sideroblasts
• 1-2 years in refractory anaemia with excess blasts and in chronic myelomonocytic leukaemia
• less than 1 year in refractory anaemia with excess blasts in transformation

Poor prognostic factors for survival:

• more than 5% blast cells in the marrow
• very low blood counts
• patients with abnormalities of chromosome 5 or 7 have a particularly poor prognosis. Certain subgroups, such as patients with an interstitial deletion of 5q associated with refractory anaemia and thrombocytosis, can expect a relatively good outcome

Reference:

1. Greenberg PL, Tuechler H, Schanz J, et al. Revised international prognostic scoring system for myelodysplastic syndromes. Blood. 2012 Sep 20;120(12):2454-65.