Karyotype at diagnosis, subsequent leukemic transformation and survival in myelodysplastic syndrome. Czechoslovak MDS Cooperative Group.

240 patients with MDS studied cytogenetically at diagnosis between 1981 and 1990 were followed until death or until April 1992 to evaluate the prognostic significance of FAB classification, age and karyotype. 61 patients (25.4%) subsequently transformed into AML and 176 (73.3%) died 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 chromosomal abnormalities at the initial evaluation identified a subgroup of patients with a high risk of a short survival and/or subsequent leukemia transformation. In refractory anemia the presence of complex chromosomal abnormalities was linked with a relative risk of 3.58 of leukemic transformation and shorter survival as compared with other cytogenetically defined groups.