Trisomy 8 finding treatment of imatinib mesylate in chronic myeloid leukemia cases

Abstract

To the Editor: We read the interesting article named “The emergence of Ph−, trisomy-8+ cells in patients with chronic myeloid leukemia treated with imatinib mesylate,” written by Feldman et al. in the journal [1Feldman E. Najfeld V. Schuster M. Roboz G. Chadburn A. Silver R.T. The emergence of Ph−, trisomy-8+ cells in patients with chronic myeloid leukemia treated with imatinib mesylate.Exp Hematol. 2003; 31: 702-707Abstract Full Text Full Text PDF PubMed Scopus (40) Google Scholar]. Also recently, a few reports had been published with negative Philadelphia results with trisomy 8 findings during the treatment of imatinib mesylate in chronic myeloid leukemia (CML) cases [2Bhaita R. Holtz M. Niu N. et al.Persistence of malignant hematopoietic progenitors in chronic myelogeneous leukemia patients in complete cytogenetic remission following imatinib mesylate treatment.Blood. 2003; 101: 4701-4707Crossref PubMed Scopus (458) Google Scholar, 3Yamamato Y. Ishii K. Nomura S. Fukuhara S. Clonal Ph− hematopoiesis with trisomy 8 in chronic myeloid leukemia during the imatinib therapy.Rinsho Ketuski. 2004; 45: 164-166PubMed Google Scholar]. Trisomy 8 was found without myelodysplasia findings in these cases [3Yamamato Y. Ishii K. Nomura S. Fukuhara S. Clonal Ph− hematopoiesis with trisomy 8 in chronic myeloid leukemia during the imatinib therapy.Rinsho Ketuski. 2004; 45: 164-166PubMed Google Scholar, 4Terre C. Eclache V. Rousellot P. et al.Report of 34 patients with clonal chromosomal abnormalities in Philadelphia-negative cases during imatinib treatment of Philadelphia-positive chronic myeloid leukemia.Leukemia. 2004; 18: 1340-1346Crossref PubMed Scopus (133) Google Scholar]. Recently, we also observed two CML cases that had imatinib mesylate treatment with trisomy 8 without Philadelphia chromosome findings. Molecular analysis results were also supported by our BCR/ABL− results. No myelodysplasia was observed in our cases, as in the other cases in literature. Trisomy 8 was reported in CML cases during the progression phase [5Heim S. Mitelman F. Chronic myeloid leukemia.in: Heim S. Mitelman F. Cancer Cytogenetics. 2nd ed. Wiley Liss Inc., New York1995: 33-68Google Scholar]. This condition (finding trisomy 8 in Philadelphia-negative cell populations in CML) was explained as a result of selective inhibition of Philadelphia-positive cells with imatinib mesylate therapy [1Feldman E. Najfeld V. Schuster M. Roboz G. Chadburn A. Silver R.T. The emergence of Ph−, trisomy-8+ cells in patients with chronic myeloid leukemia treated with imatinib mesylate.Exp Hematol. 2003; 31: 702-707Abstract Full Text Full Text PDF PubMed Scopus (40) Google Scholar]. Also, patients in complete cytogenetic response with imatinib mesylate treatment need to be followed carefully for the risk of relapse [2Bhaita R. Holtz M. Niu N. et al.Persistence of malignant hematopoietic progenitors in chronic myelogeneous leukemia patients in complete cytogenetic remission following imatinib mesylate treatment.Blood. 2003; 101: 4701-4707Crossref PubMed Scopus (458) Google Scholar]. Despite complete cytogenetic response, selective inhibition of BRC/ABL tyrosine kinase by using imatinib mesylate in the treatment of chronic myeloid leukemia seems insufficient in some cases according to these results. Perhaps an alternative treatment protocol with imatinib mesylate should be improved.