[Clinical implications of chromosome analysis in myelodysplastic syndrome].

We attempted to identify the cytogenetic significance in predicting the prognosis of patients with myelodysplastic syndrome (MDS). From the results, we established scoring system (Bournemouth scoring+cytogenetic scoring: 3 for > or = 3 chromosomal abnormalities; 1 for -7/7q-, +8, 2 abnormalities); patients with score of > or = 5 had significant worse prognosis than that with score 0-2. Moreover, RARS with complex abnormalities consists of specific subtype showing a high leukemic rate with a high mortality rate. MDS with hypocellular marrow showed prognosis similar to those with typical MDS, while those with minimal dysplasia had prognosis similar to those with aplastic anemia. Patients with MDS were categorized into 3 subtypes, i.e., early disease-evolution, late disease-evolution, and no disease-evolution group. About 50% of patients with complex abnormalities showed early disease-evolution, while the remaining died before disease-evolution. In patients showing late disease-evolution, no cytogenetic factor are informative to predict the timing of disease-evolution, except percentage of marrow blasts at the diagnosis.