Genetic variability of glutathione S-transferases influences treatment outcome of breast cancer.

We investigated the relationship between the clinical outcome and the GSTM1 null/present, GSTT1 null/present, and GSTP1 IIe105Val polymorphisms in breast cancer patients with chemotherapy. A total of 420 consecutive breast cancer patients diagnosed between January 2010 and December 2011 were eligible for inclusion in our retrospective study. The designs of the assay and SNP genotyping of GSTM1 null/present, GSTT1 null/present, and GSTP1 IIe105Val were performed using the Sequenom MassARRAY platform. In the univariate analysis, patients who carried TT genotype and CT + TT genotype of GSTP1 IIe105Val showed a significant poorer tumor response to chemotherapy when compared with CC genotype (for TT genotype, adjusted OR = 0.44, 95 % CI = 0.22-0.89; for CT + TT genotype, adjusted OR = 0.59, 95 % CI = 0.39-0.92). By Cox multivariate analysis, TT genotype and CT + TT genotype were associated with increased risk of death from breast cancer, and the relationship was more obvious after being adjusted by potential confounding factors (for TT genotype, adjusted OR = 4.23, 95 % CI = 2.33-8.76; for CT + TT genotype, adjusted OR = 2.53, 95% CI = 1.60-4.03). Polymorphism of GSTP1 IIe105Val might affect the clinical outcome in breast cancer patients.