Extended cytogenetic follow-up and clinical progress in patients with myelodysplastic syndromes (MDS).

198 patients with MDS were followed cytogenetically for up to 90 months. There were significant differences in survival between patients with a normal karyotype, single abnormalities (p < 0.05) and multiple abnormalities (p < 0.0001). Survival differences were also seen in each of the FAB sub-types but were only significant in RAEB/RAEB-t and CMML (p = 0.001) where a normal karyotype was associated with prolonged survival. Single and multiple abnormalities of chromosomes 7 and 8 but only multiple abnormalities of chromosome 5 were also associated with reduced survival. 126 patients were successfully investigated on more than one occasion. Karyotype evolution occurred in 15 and was associated with reduced overall survival in those patients who had previously been karyotypically normal (p < 0.05). Median survival following evolution was only 10 months. 29 patients developed leukaemia. The incidence of transformation was significantly higher in patients with multiple abnormalities than in those with a normal karyotype (p < 0.05) or single abnormalities (p < 0.05).