KARYOTYPE AT DIAGNOSIS, SUBSEQUENT LEUKEMIC TRANSFORMATION AND SURVIVAL IN MYELODYSPLASTIC SYNDROME

240 patients with MDS studied cytogenetically at diagnosis between 198 1 and 1990 were followed until death or until April 1992 to evaluate t he prognostic significance of FAB classification, age and karyotype. 6 1 patients (25.4%) subsequently transformed into AML and 176 (73.3%) d ied during the follow-up period. Patients with blastic MDS types had a shorter survival and a higher probability of leukemic transformation. The younger age increased the probability of leukemic transformation, but was associated with a longer survival. The absence of analyzable mitoses was associated with a shorter survival. The complex chromosoma l abnormalities at the initial evaluation identified a subgroup of pat ients with a high risk of a short survival and/or subsequent leukemic transformation. In refractory anemia the presence of complex chromosom al abnormalities was linked with a relative risk of 3.58 of leukemic t ransformation and shorter survival as compared with other cytogenetica lly defined groups.