Chromosome abnormalities and karyotypic evolution in 83 patients with myelodysplastic syndrome and predictive value for prognosis.

In a chromosome study of 83 patients with myelodysplastic syndrome (MDS), 50 showed a clonally abnormal karyotype. The most frequent abnormalities were the whole or a partial loss of the long arm of chromosome 7 (-7 or 7q-) (14 patients) and a partial loss of the long arm of chromosome 5 (5q-) (11 patients). Twenty patients with 5q- and/or -7 or 7q- had a shorter survival (median, 5 months) than those with other abnormal karyotypes (22 months) or those with a normal karyotype (28 months). In this series 30 patients were examined cytogenetically on two or more occasions during the course of their illness. Ten patients showed a further karyotypic alteration from the initial findings, and, concomitantly, their disease progressed in severity including overt leukemia. These patients had a shorter survival (median, 2 months) after the chromosome reanalysis than the other 20 patients who did not have further karyotypic changes (21 months). Thus, the prognosis of patients with MDS can be predicted more accurately by reanalyzing the chromosomes after the initial analysis.