MDR1 gene polymorphisms and imatinib response in chronic myeloid leukemia: a meta-analysis.

Background:MDR1 gene polymorphisms were demonstrated to be associated with interindividual variability of imatinib response for chronic myeloid leukemia (CML) patients in several studies; however, the results have been inconclusive. Materials & methods: To clarify the effect of common MDR1 variants on clinical response to imatinib, we performed a meta-analysis to quantify the accumulated information from genetic association studies. After a thorough search of the published literature, we undertook a meta-analysis to evaluate the effect of MDR1 C1236T, G2677T and C3435T polymorphisms on imatinib response. Results: Our pooled data showed a significant association between MDR1 C1236T polymorphism and the increasing risk of imatinib resistance in Asian CML patients. However, no significant association was found for the MDR1 G2677T or C3435T polymorphisms in an Asian CML population as well as a Caucasian CML population. Conclusion: The synonymous MDR1 C1236T polymorphism might be a risk factor for nonoptimal clinical response to imatinib in Asian CML patients. Original submitted 19 August 2013; Revision submitted 10 January 2014