Outcome prediction by the transcript level of BCR-ABL at 3 months in patients with chronic myeloid leukemia treated with imatinib-a single institution historical experience

The BCR-ABL transcript level (≤10%) at 3 months after tyrosine kinase inhibitors can predict long term outcome in the patients with chronic myeloid leukemia in chronic phase (CML-CP). However, the significance of transcript level was still not determined in different risk groups of patients. A total of 299 patients with CML-CP were enrolled and stratified according to prior interferon-α (IFN) treatment, age, and interval time between diagnosis and imatinib treatment to investigate the prediction value of BCR-ABL transcript level for overall survival (OS), event-free survival (EFS), progression-free survival (PFS). Univariate and multivariate analysis proved that BCR-ABL transcript level at 3 months were associated with the treatment outcome. However, in the patients with prior IFN treatment, younger age, and longer interval between diagnosis and IM treatment, the predictive value of transcript value remain obscure in terms of EFS, PFS and OS, respectively, as well as cumulative incidence of PCyR, CCR, MMR and CMR. In conclusion, the transcript level of BCR-ABL at 3 months could serve as a predictive parameter, but should be used with caution.