Monitoring of BCR-ABL levels in chronic myeloid leukemia patients treated with imatinib in the chronic phase: the importance of a major molecular response

• Autor(a) principal: Machado,Melissa Pereira
• Data de Publicação: 2011
• Outros Autores: Tomaz,Juarez Pires, Lorand-Metze,Irene, Souza,Cármino Antonio de, Vigorito,Afonso Celso, Delamain,Marcia Torresan, Bendit,Israel, Pereira,Noemi Farah, Pagnano,Katia Borgia Barbosa
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Revista brasileira de hematologia e hemoterapia (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-84842011000300014
• topic: Polymerase chain reaction; Monitoring; Leukemia, myelogenous, chronic, BCR-ABL positive

BACKGROUND: Real time PCR has become the most common technique to monitor BCR-ABL transcript levels of patients treated with kinase inhibitors. The aim of this study was to evaluate BCR-ABL levels of chronic myeloid leukemia patients treated with imatinib in the chronic phase and correlate the response to therapy and event-free survival. METHODS: BCR-ABL levels were measured in peripheral blood cell samples using Real time PCR at diagnosis and then every 3 months after starting therapy with imatinib. Major molecular response was defined as a three-log reduction from the standardized baseline value. Major molecular response values were adjusted to international scale using a conversion factor of 1.19. The results are reported as a BCR-ABL/ABL ratio (%). RESULTS: Hematological, major cytogenetic and complete cytogenetic responses were achieved by 57 (95%), 45 (75%) and 38 (63%) patients, respectively. Twenty-four out of sixty patients achieved a major molecular response (40%) in a median time of 8.5 months. Overall survival and event free survival were higher for patients with (100%) versus patients without (77%) a complete cytogenetic response (p-value = 0.01) at 48 months. Patients with complete cytogenetic response and major molecular response had a higher event free survival compared to patients with complete cytogenetic response but without major molecular response (p-value = 0.007). CONCLUSION: In conclusion, the prognostic impact of achieving complete cytogenetic response and a major molecular response and also the importance of molecular monitoring in the follow-up of chronic myeloid leukemia patients were demonstrated.