title: Influence of late treatment on how chronic myeloid leukemia responds to imatinib.
abstract: BACKGROUND
  In Brazil, patients with chronic myeloid leukemia (CML) in the chronic phase were not given first-line imatinib treatment until 2008. Therefore, there was a long period of time between diagnosis and the initiation of imatinib therapy for many patients. This study aims to compare the major molecular remission (MMR) rates of early versus late imatinib therapy in chronic phase CML patients.
  
  
  METHODS
  Between May 2002 and November 2007, 44 patients with chronic phase CML were treated with second-line imatinib therapy at the Hematology Unit of the Ophir Loyola Hospital (Belém, Pará, Brazil). BCR-ABL transcript levels were measured at approximately six-month intervals using quantitative polymerase chain reaction.
  
  
  RESULTS
  The early treatment group presented a 60% probability of achieving MMR, while the probability for those patients who received late treatment was 40%. The probability of either not achieving MMR within one year of the initiation of imatinib therapy or losing MMR was higher in patients who received late treatment (79%), compared with patients who received early treatment (21%, odds ratio=5.75, P=0.012). The probability of maintaining MMR at 30 months of treatment was 80% in the early treatment group and 44% in the late treatment group (P=0.0005).
  
  
  CONCLUSIONS
  For CML patients in the chronic phase who were treated with second-line imatinib therapy, the probability of achieving and maintaining MMR was higher in patients who received early treatment compared with those patients for whom the time interval between diagnosis and initiation of imatinib therapy was longer than one year.
authors.affiliation: Universidade Federal do Pará, Instituto de Ciências Biológicas, Belém/PA, Brazil.
authors.forename: Ana Carolina Costa
authors.initials: AC
authors.lastname: Scerni
authors.forename: Leonardo Azevedo
authors.initials: LA
authors.lastname: Alvares
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Beltrão
authors.forename: Iê Regina
authors.initials: IR
authors.lastname: Bentes
authors.forename: Tereza Cristina
authors.initials: TC
authors.lastname: Azevedo
authors.forename: Alessandra Quinto
authors.initials: AQ
authors.lastname: Bentes
authors.forename: José Alexandre Rodrigues
authors.initials: JA
authors.lastname: Lemos
mesh_terms: D000328:Adult; D000368:Aged; D001549:Benzamides; D005260:Female; D016044:Fusion Proteins, bcr-abl / Q000378:metabolism; D006801:Humans; D000068877:Imatinib Mesylate; D053208:Kaplan-Meier Estimate; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000627:therapeutic use*; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D011743:Pyrimidines / Q000627:therapeutic use*; D012074:Remission Induction; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D001549:Benzamides; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D016044:Fusion Proteins, bcr-abl
references.citation: N Engl J Med. 2002 Feb 28;346(9):645-52
references.pmid: 11870241
references.citation: Science. 1990 Feb 16;247(4944):824-30
references.pmid: 2406902
references.citation: Leukemia. 2003 Dec;17(12):2318-57
references.pmid: 14562125
references.citation: Clin Cancer Res. 2003 Jan;9(1):160-6
references.pmid: 12538464
references.citation: Blood. 2006 Jul 1;108(1):28-37
references.pmid: 16522812
references.citation: Leukemia. 1996 Jul;10(7):1217-21
references.pmid: 8684005
references.citation: N Engl J Med. 2003 Oct 9;349(15):1423-32
references.pmid: 14534335
references.citation: Blood. 2003 Jun 15;101(12):4701-7
references.pmid: 12576334
references.citation: Leukemia. 2003 Dec;17(12):2474-86
references.pmid: 14562124
references.citation: Proc Natl Acad Sci U S A. 1987 Sep;84(18):6558-62
references.pmid: 3498165
references.citation: N Engl J Med. 1988 Oct 13;319(15):990-8
references.pmid: 3047582
references.citation: Int J Hematol. 2007 Feb;85(2):132-9
references.pmid: 17321991
references.citation: N Engl J Med. 2002 Feb 28;346(9):683-93
references.pmid: 11870247
references.citation: Cancer. 2007 Mar 15;109(6):1138-45
references.pmid: 17315159
references.citation: Best Pract Res Clin Haematol. 2002 Mar;15(1):159-78
references.pmid: 11987922
references.citation: Genet Mol Res. 2005 Dec 30;4(4):803-11
references.pmid: 16475128