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WPSS (WHO classification-based Prognostic Scoring System) for Myelodysplastic Syndrome

Time-dependent survival and leukemic-evolution risk in myelodysplastic syndrome.

WPSS (WHO classification-based Prognostic Scoring System) for Myelodysplastic Syndrome
WHO subtype
Cytogenetic risk group (IPSS)
Regular red-cell transfusion dependence (≥1 unit/8 weeks)
Result0 points

WPSS risk group: Very low, with approximate median overall survival ~141 months.

Risk group
Very low
Approx. median survival
~141 months

When to use

  • Estimating survival and risk of leukemic evolution in MDS at any point during the disease course (unlike IPSS, which is validated only at diagnosis).
  • Guiding timing of intensified treatment or transplant referral as transfusion needs or cytogenetics evolve.

Formula

WPSS = WHO subtype points (RA/RARS/isolated 5q-=0, RCMD=1, RAEB-1=2, RAEB-2=3) + IPSS cytogenetic risk (good=0, intermediate=1, poor=2) + transfusion requirement (no=0, regular=1). Range 0-6, grouped as very low (0), low (1), intermediate (2), high (3-4), very high (5-6).

Pearls and pitfalls

  • Unlike the IPSS, WPSS can be recalculated at any time during follow-up as WHO subtype, cytogenetics, and transfusion needs change.
  • A later refinement substitutes an objective severe-anemia threshold (Hgb <9 g/dL men, <8 g/dL women) for transfusion dependence to reduce subjectivity.

References

  1. Malcovati L, Germing U, Kuendgen A, et al. Time-dependent prognostic scoring system for predicting survival and leukemic evolution in myelodysplastic syndromes. J Clin Oncol. 2007;25(23):3503-3510.
  2. Malcovati L, Della Porta MG, Strupp C, et al. Impact of the degree of anemia on the outcome of patients with myelodysplastic syndrome and its integration into the WHO classification-based Prognostic Scoring System (WPSS). Haematologica. 2011;96(10):1433-1440.