Application of different prognostic scoring systems and comparison of the FAB and WHO classifications in Korean patients with myelodysplastic syndrome

We retrospectively studied 227 patients with MDS (1) to identify the prognostic factors of survival and acute leukemia evolution in Korean patients with MDS, (2) to apply different prognostic scoring systems to the same group of patients, and (3) to compare the FAB with the WHO classification. Six scoring systems were applied to the patients, and the FAB and WHO classifications were compared. The patients' median age was 57 years. The median survival time was 21 months, and age, dysgranulopoiesis and the IPSS cytogenetic groups were independent prognostic factors for survival. Acute leukemia occurred in 34 patients, and the cumulative incidence was 27.1% at 3 years. Marrow blast percentage was the only independent prognostic factor for acute leukemia evolution. Most scoring systems successfully discriminated risk groups for survival and acute leukemia evolution, but patient distribution into risk groups varied according to the scoring systems. Refractory cytopenia with multilineage dysplasia and RAEB II seemed to have different prognoses from RA or RARS and RAEB I, respectively. In summary, our MDS patients had different disease natures from those of Western countries regarding clinical features, prognostic factors and cytogenetic profiles. Although the WHO classification seems to improve the FAB classification, further studies are warranted to validate the utility of the WHO classification before it is accepted for routine clinical use. Our study has the limitations of retrospective analysis, and our results should be verified in future prospective studies.