Genetic Polymorphism of the Glutathione S-Transferase M1 and Development of Breast Cancer

Glutathione S-transferases (GSTs) are encoded by a superfamily of genes and play a role in the detoxification of potential carcinogens. The human GSTs are divided into four classes: alpha, mu, pi and theta. Previous studies indicated that the absence of the Glutathione S-Transferase M1 (GSTM1) protein correlated with an increased risk of developing some types of cancers. Association between specific genotype and the development of breast cancer is still an open question. In the present study, the association between genetic polymorphism in the GSTM1 and susceptibility to breast cancer was investigated. The genetic polymorphism of the GSTM1 in exon 5 to exon 6 segments was detected by PCR in 59 patients with breast cancer and 59 normal subjects. The frequency of the GSTM1 null genotype in control and patient groups was 39.0% and 50.8% respectively. There was no significant association between null genotype of the GSTM1 and susceptibility to breast cancer (X2 = 1.63, df = 1, p >0.05).