Cytogenetic profile of 1,863 Ph/BCR-ABL-positive chronic myelogenous leukemia patients from the Chinese population

Cytogenetic analyses of chronic myelogenous leukemia (CML) have been performed previously in a large number of reports, but systematical research based on large sample sizes from the Chinese population is seldom available. In this study, we analyzed the cytogenetic profiles of 1,863 Philadelphia (Ph)/BCR-ABL-positive CML patients from a research center in China. Of 1,266 newly diagnosed CML patients, the median age was 41 years, which is younger than the median age of diagnosis in western populations. The incidence of additional chromosome abnormalities (ACA) was 3.1% in newly diagnosed chronic phase (CP), 9.1% in CP after therapy, 35.4% in accelerated phase, and 52.9% in blast crisis (BC), reflecting cytogenetic evolution with CML progression. A higher prevalence of ACA was observed in variant Ph translocations than in standard t(9;22) in the disease progression, especially in BC (88.2% vs. 50%, P = 0.002). Moreover, a hyperdiploid karyotype and trisomy 8 were closely correlated with myeloid BC, while a hypodiploid karyotype and monosomy 7 were associated with lymphoid-BC. Among subsets of myeloid-BC, myeloid-BC with minimal differentiation had a higher ACA rate than myeloid-BC with granulocytic differentiation (80% vs. 46.8%, P = 0.009) and myeloid-BC with monocytic differentiation (80% vs. 42.9%, P = 0.006). These data provide novel insights into cytogenetics of CML within the Chinese population.