Myelodysplastic syndromes according to FAB and WHO classification. Single center experience

The results of clinical and laboratory observations of 119 MDS patients divided acc. to FAB, and - after excluding RAEB-t and CMML groups -- of 95 patients divided accordingly to WHO classification are presented. The diagnosis of MDS was based on medical interview, physical examination, blood biochemistry, peripheral blood (PB) and bone marrow (BM) cytomorphology and cytochemistry, trephine biopsy and cytogenetic examination. All hematologic examinations were done according to routine methods. Cytogenetic analyses were carried out on BM cells from 24-48 h cultures in standard conditions. At least 15-20 GTG-banded metaphases were analyzed in every patient. The survival time (ST) of patients differed significantly between the FAB or WHO groups, with p=0.0004 for FAB and p=0.02 for WHO. The progression to AML was more common in less favorable groups, with p=0.0001 for FAB and p=0.00016 for WHO. The distribution of IPSS prognostic index among the groups showed statistically significant difference (p=0.0004 for FAB, and p=0.0001 for WHO), whereas the distribution of karyotypic abnormalities did not. However, in univariate analysis statistically significant influence on ST showed, beside the both classification systems: cytogenetics, the presence of blasts in PB, age and IPSS index. In multivariate analysis the sole independent prognostic factors were: PB blasts and cytogenetics. The authors conclude that the WHO classification offers a good prognostic tool for MDS patients. However, the karyotype and the presence of blasts in PB should always be taken into account.