Objective: To evaluate the cytogenetic and molecular genetic features of chronic myeloid leukemia (CML) in Chinese.
Methods: A total of 1193 CML patients were retrospectively studied. Chromosome preparation of bone marrow cells was made using direct and short-term culture. Karyotype and bcr-abl fusion genes were analyzed by R-banding, RT-PCR, respectively.
Results: In the 1193 cases, 98.07% was Ph chromosome positive (Ph+) and 1.93% negative (Ph-). In the Ph+ patients, 95.64% was classical Ph and 4.36% variant rearrangements. Additional genetic changes were demonstrated in 11.88% of classical Ph cases. Cytogenetic clonal evolution was found in 7.94% of patients in chronic phase (CP), 27.78% in accelerated phase (AP), and 49. 04% in blast crisis (BC). Among the classical Ph cases, +Ph, +8, -21 were found in 14.62%, 10.77% and 7.69% of them respectively. In patients in BC and AP, the most common additional chromosome changes were + Ph (28.57%), +8 (16.67%) and +19 (7.14%), while in CP, -21 (10.26%), +Ph (8.97%), and +8 (8.97%). The combination of +Ph and +8 (3.60%) was the most frequent of combination pattern. 524 cases were investigated for bcr-abl fusion gene, and 54.01% was b3a2 (+) and 27.67% b2a2 (+).
Conclusion: In Chinese CML patients seem to have their unique features in terms of cytogenetic clonal evaluation.