title: Imatinib mesylate-sensitive blast crisis immediately after discontinuation of imatinib mesylate therapy in chronic myelogenous leukemia: report of two cases.
abstract: Although imatinib mesylate has shown encouraging activity in chronic myelogenous leukemia (CML), disease progression during therapy has been observed, manifested by clonal expansion of imatinib mesylate-resistant leukemia cells. On the other hand, myelosuppression related to treatment of imatinib mesylate is often managed with temporary interruption of treatment or dose reduction. We here report two CML patients who had imatinib mesylate-sensitive blast crisis (BC) immediately after discontinuation of imatinib mesylate therapy. The patients discontinued therapy because of neutropenia. Although there was no evidence of blastic phase during therapy, BC occurred 2 weeks after the withdrawal of treatment in both cases. Interestingly, additional chromosomal abnormalities were detected following the withdrawal of imatinib mesylate and disappeared by re-introduction of this agent. The same doses of imatinib mesylate was still effective and remission was sustained with imatinib mesylate alone again. Our report suggests the possibility that withdrawal of imatinib mesylate may lead to proliferation of blast clones even in patients showing good responses to imatinib mesylate without signs of disease progression.
authors.affiliation: First Department Internal Medicine, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan. jtsukada@med.uoeh-u.ac.jp
authors.forename: Takehiro
authors.initials: T
authors.lastname: Higashi
authors.forename: Junichi
authors.initials: J
authors.lastname: Tsukada
authors.forename: Chiaki
authors.initials: C
authors.lastname: Kato
authors.forename: Atsushi
authors.initials: A
authors.lastname: Iwashige
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Mizobe
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Machida
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Morimoto
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Ogawa
authors.forename: Yoko
authors.initials: Y
authors.lastname: Toda
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Tanaka
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D001549:Benzamides; D001752:Blast Crisis / Q000188:drug therapy* / Q000473:pathology; D001853:Bone Marrow / Q000473:pathology; D002869:Chromosome Aberrations; D016313:Genes, abl / Q000235:genetics; D006801:Humans; D000068877:Imatinib Mesylate; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D007958:Leukocyte Count; D008297:Male; D009503:Neutropenia / Q000139:chemically induced; D010879:Piperazines / Q000008:administration & dosage* / Q000009:adverse effects; D010976:Platelet Count; D011743:Pyrimidines / Q000008:administration & dosage* / Q000009:adverse effects; D012333:RNA, Messenger; D012074:Remission Induction
chemical_list: D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D012333:RNA, Messenger; D000068877:Imatinib Mesylate