WHO classification-based prognostic scoring system for myelodysplasis

Prognosis of myelodysplastic syndromes (MDS)

1. Sum the scores for each factor (WHO category, karyotype, transfusion requirement

ScoreWHO CategoryKaryo­type (1)Trans­fusion require­ment (2)
0RA, RARS, 5q-GoodNone
1RCMDInter­mediateRegular
2RAEB-1Poor-
3RAEB-2--
(1) Karyotypes: Good = normal, -Y, del(5q-) only, del(20q-) only. Poor = complex (≥3 abnormalities), or chromosome 7 abnormalities. Intermediate = all others.
(2) Transfusion dependency is defined as at least one red transfusion every 8 weeks over a period of 4 months.

2. Use summed scores to determine risk category and prognosis

ScoreRisk categoryMedian OS
(months)
2 year proba­bility of
progres­sion to AML
0Very low1413%
1Low666%
2Inter­mediate4821%
3 - 4High2638%
5 - 6Very high980%