[Early blastic transformation within a year of imatinib treatment in 2 cases of chronic myeloid leukemia].

ABSTRACT

We report herein on two rare cases of newly diagnosed chronic myeloid leukemia, which developed early blastic transformation within a year of imatinib treatment. Case 1 is a 22-year-old Japanese female, who underwent gradual blastic transformation with the increase of a resistant clone, which cytogenetically evolved right after she reached complete hematologic remission. Case 2 is a 24-year-old Japanese male, who underwent sudden transformation after 8 months treatment with imatinib mesylate following complete cytogenetic response. Although a sudden blastic transformation is extremely rare, the occurrence of such events even among the low-risk, good responding patients highlights the need for continued, rigorous monitoring by sensitive analysis, such as quantitative PCR. In order to accomplish the early eradication of minimal residual disease, the therapeutic strategy for chronic myeloid leukemia has to be defined in the era of imatinib, considering the application of allogeneic stem cell transplantation, which is currently the only curative treatment.