Polymorphisms: GSTO1*A140D (C419A; rs4925), GSTO2*N142D (A424G; rs156697)Main findings: - no association between GSTO1-1 and GSTO2-2 genotypes and the risk of breast cancer;- higher prevalence of homozygous wild-type GSTO1*A140 genotype is significantly correlated with advanced-stage breast cancer. This evidence concerns the gene GSTO2 and breast cancer.