OBJECTIVESTo explore the effect of additional chromosomal abnormalities on the prognosis and outcome of CML-CP patients receiving imatinib therapy.

METHODSThe clinical and genetic data of 589 CML-CP patients receiving imatinib treatment between May 2009 and October 2014 in the 1st Affiliated Hospital of Soochow University were analyzed, the 589 patients were divided into 5 groups according to the karyotypes at the initial diagnosis. The OS(overall survival), PFS (progression-free survival), EFS (event-free survival), Cumulative MMR (major molecular remission) and Cumulative CCyR (complete cytogenetic remission) were calculated by using the Kaplan-Meier method and compared by using the log-rank text by Graphpad 6.0. The χ test was used to compare the frequency of optimal molecular response at 3, 6, 12 months among the 5 groups.

RESULTSThere was significant difference about the frequency of optimal molecular response at 3 and 6 months between CML-CP patients with additional chromosomal abnormalities and those with classic t(9;22) ［50%（12/24） vs. 73.94%(261 /353), P<0.05; 50%(10 /20) vs. 72.05%(232 /322) (P<0.05)］, and the same significant difference was found at 6 months between the group with variant translocations and that with classic t(9;22) ［53.3% (16 /30) vs. 72.05%(232 /322) (P<0.05)］. The P values of cumulative CCyR (P<0.05) and EFS (P<0.01) for 4 years were statistically significant between CML-CP patients with additional chromosomal abnormalities and the other 4 groups. Compared one to another, there was the significant difference in cumulative CCyR and EFS for 4 years between CML-CP patients with additional chromosomal.abnormalities and those with classic t(9;22) (47.25% vs. 84.01%)(P<0.05); (75.03% vs. 90.01%)(P<0.01).

CONCLUSIONThe additional chromosomal abnormalities influence the outcome of CML-CP patients receiving imatinib treatment, which make poor prognosis.