Association Between Glutathione-S-Transferase Gene Polymorphisms and Responses to Tyrosine Kinase Inhibitor Treatment in Patients with Chronic Myeloid Leukemia: A Meta-analysis

Background: Although many earlier studies revealed an effect of glutathione-S-transferase (GST) gene polymorphisms on tyrosine kinase inhibitor (TKI) treatment responses in chronic myeloid leukemia (CML) patients, the significance of this relationship remains controversial. Objective: This study aimed to review and meta-analyze treatment responses to TKIs in patients with CML and GST gene polymorphisms, including GSTT1, GSTM1, and GSTP1. Patients and Methods: We searched four medical databases, PubMed, Web of Science, the Cochrane Library, and Embase, by using keywords related to GST gene polymorphisms and clinical responses in CML patients receiving TKI treatment. The meta-analysis was performed using RevMan version 5.3 and Comprehensive Meta-Analysis software version 3.0. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to examine the association between GSTT1, GSTM1, and GSTP1 polymorphisms and TKI treatment responses in patients with CML. Results: The null polymorphisms of GSTT1 and GSTM1 did not affect TKI treatment responses, while the GSTP1 Ile105Val polymorphism had a significant impact on responses to TKI. Patients who were GSTP1 variant allele carriers (AG + GG) had poor responses to TKI treatment compared to patients who were wild-type homozygote carriers (AA) (OR 1.85, 95% CI 1.31–2.62; p < 0.001). Conclusions: This meta-analysis of patients with CML showed that G allele carriers with GSTP1 Ile105Val polymorphism had significantly worse responses to TKI treatment than wild-type homozygote carriers.