Polymorphisms of glutathione S-transferase Mu 1 (GSTM1), Theta 1 (GSTT1), and Pi 1 (GSTP1) genes and epithelial ovarian cancer risk

BACKGROUND: Exposure of ovarian cells to estrogen, which is detoxified by glutathione S-transferases (GSTs), has been associated with epithelial ovarian cancer (EOC) development. OBJECTIVES: We tested in this study whether the GSTM1, GSTT1 and GSTP1 Ile105Val polymorphisms alter the risk of EOC. MATERIALS AND METHODS: Genomic DNA from 132 EOC patients and 132 controls was analyzed by polymerase chain reaction and restriction fragment length polymorphism methods. The differences between groups were analyzed by χ ^{2} or Fisher's exact test. RESULTS: The frequencies of GSTP1 Ile/Ile (57.6% versus 45.5%, P=0.03), GSTM1 null plus GSTP1 Ile/Ile (43.5% versus 25.8%; P=0.03) and GSTM1 null plus GSTT1 null plus GSTP1 Ile/Ile (30.3% versus 7.7%; P=0.007) genotypes were higher in patients than in controls. Individuals with the respective genotypes had a 1.80 (95% CI: 1.06-3.06), 2.38 (95% CI: 1.08-5.24) and 11.28 (95%CI: 1.95-65.30)-fold increased risks of EOC than those with the remaining genotypes. CONCLUSIONS: Our data present preliminary evidence that GSTM1, GSTT1 and GSTP1 polymorphisms, particularly in combination, constitute important inherited EOC determinants in individuals from Southeastern Brazil.