Résumé
BACKGROUND: Cytogenetic study is important in prediction of prognosis and evaluation of treatment effect in leukemia. The cytogenetic aberrations of leukemia are nonrandom, but uneven geographic distribution of specific abnormalities have been reported in a few studies. So we analyzed cytogenetic study to find these uneven distribution patterns. METHODS: The conventional cytogenetic study was performed for 515 cases with acute and chronic leukemia on initial diagnosis. The results were analysed in each subtypes classified according to FAB criteria. RESULTS: The aberration rate was 62.0% in acute myelogenous leukemia (AML), 72.0% in acute lymphoblastic leukemia (ALL), 92.8% in chronic myelogenous leukemia (CML), 37.5% in chronic lymphocytic leukemia (CLL), 56.9% in myelodysplastic syndrome (MDS) and 36.4% in acute undetermined leukemia. The frequent anomalies were t(8;21)(q22;q22), t(15;17)(q22;q11), -Y, +8, +21 in AML, t(9;22)(q34;q11), del(6q), +8, t(1;19)(q23;p13), +21, -20 in ALL, -7/del(7q), +8, del(12p), +11 in MDS. Philadelphia chromosome was found in 94.8% of CML and +22q-, +8 was frequent secondary changes. The incidence of t(8;21)(q22;q22) in M2, t(15;17)(q22;q11) in M3, t(9;22)(q34;q11) in ALL and -5/del5q, -7/del7q in MDS were 54.9%, 95.2%, 23.6%, 4.0% and 40.0%, respectively. CONCLUSION: There were no marked differences in distribution pattern of common aberrations compared to previous reports. But the frequency of some anomalies showed specific findings. The incidence of t(8;21) in M2 subtype and t(9;22)(q34;q11) in ALL were higher in oriental countries including our results than in western countries. The incidence of -5/del(5q) in MDS was lower in oriental countries. These findings suggest the geographic heterogeneity which may give some help to investigate the genetic and environmental influence on the karyology of tumors.