[Cytogenetic analysis of 600 cases with chronic myelogenous leukemia].

OBJECTIVE: This was a retrospective analysis of cytogenetic data from 600 cases with chronic myelogenous leukemia (CML) to investigate the features of Ph chromosome and its significance. METHODS: Bone marrow direct method and/or short-term culture were used to prepare the chromosomes and karyotype analysis was performed with R-banding technique. RESULTS: 30 cases (5%) were Ph negative; 570 cases (95%) were Ph positive. 535 cases (93.8%) had standard Ph translocation;34 cases(5.9%) had variant translocation, including 13 cases (2.2%) with simple variant translocation, 13 cases (2.2%) with complex variant translocation and 8 cases (1.4%) with masked Ph chromosome. 526 cases (92.2%) had 100% of Ph positive cells; 44 cases (7.7%) had normal karyotype in partial or all metaphases after treatment such as allogeneic bone marrow transplantation, interferon and pulse hydroxyurea therapy, but conventional chemotherapy had no effect on the percentage of Ph positive cells. 50.6% of Ph positive CML with blast crisis had extra chromosomal abnormalities, of which, the most common ones were +8(46.1%),2 Ph(33.9%) and i(17q) (23%) in descending order. CONCLUSION: These facts indicate that chromosome examinations not only help diagnose and differentiate CML,but also help predict the blast crisis, evaluate the therapeutic effect, and make a cytogenetic classification for CML.