[Clinical and cytogenetical study on subacute myeloid leukemia in myelodysplastic syndromes]

To discuss from the clinical and cytogenetic aspect that part of patients now diagnosed as myelodysplastic syndromes (MDS) could be diagnosed early as leukemia and be classified as subacute myeloid leukemia (Sub-AML).

Totally 173 patients diagnosed as MDS according to FAB or WHO criteria with complete clinical and cytogenetical data were included in this research. Among them 42 had +8 chromosome aberration, 16 had -7/7q-, and 55 had normal karyotypes and more than 0.10 blast cells in the bone marrow. Short term culture and G-banding techniques and in some specimens fluorescence in situ hybridization (FISH) method were used to do chromosome analysis.

Among the detected chromosome aberrations, +8 was the most frequent (42.8%) and then -7/7q-(15.0%); 42 patients with +8 had median blast cell count of 0.08, within a median of 18 months follow-up period 40.0% of the patients evolved to frank leukemia (FL) and the median overall survival was 20 months. 16 patients with -7/7q- had higher blast cell count of 0.135; 43.8% of them developed into FL and the median overall survival was only 10 months within a 20-month follow-up period. 55 patients had normal karyotype but a median blast cell count of 0.148; 52.7% of them patients evolved to FL and the median overall survival was 34 months.

Both the +8 and -7/7q- groups have malignant leukemic cell clone, and run a subacute and progressive clinical course; it is suggested they might be classified into Sub-AML. We should keep close watch on the patients who have normal karyotype yet more than 0.10 blast cells, part of whom might suffer from early Sub-AML.