[Relation of karyotypic findings to chemotherapy response in patients with preleukemia]

In 1982, the French-American-British (FAB) Cooperative Group proposed the myelodysplastic syndrome (MDS), which comprised a group of heterogeneous hematologic disorders characterized by various degrees of cytopenias and a possibility of leukemic transformation. And chromosome findings of bone marrow cells from patients with this syndrome are reported to have one of the greatest prognostic significance. In our chromosome study of 97 patients with MDS, we found clonally abnormal karyotypes in 61 patients (63%), including the whole chromosome or partial loss of long arm of chromosome 7 (-7/7q-) in 18 patients and a partial loss of chromosome 5 (5q-) in 14 patients. Among these 97 patients, 26 received cytostatic chemotherapy (small dose of cytarabine; 23 patients, small dose of behenoyl Ara-C; 2, and intensive combined chemotherapy; 1) as well as supportive care. Among these 26 treated cases, pretreatment hematological characteristics or FAB subclassifications were not associated with response to chemotherapy. In contrast, only one of 9 patients with -7/7q- and/or 5q- achieved a partial remission, while 5 of 8 patients with other abnormal karyotypes and 4 of 9 patients with normal karyotype achieved a complete (4 patients) or a partial remission. In conclusion, pretreatment cytogenetic findings can predict the potential responders to this chemotherapy, and may be one of the most important factors in the selection of the treatment for this ill-managed syndrome.