ASSOCIATION OF ESTROGEN RECEPTOR Α PVU II AND XBAI GENE POLYMORPHISMS WITH BREAST CANCER RISK; RELATION TO THE AGE OF MENARCHE AND MENOPAUSE

Abstract

The association of estrogen receptor-α (ER-α) genetic polymorphisms with the risk ofbreast cancer attracts much attention because ER functions as a hormone-dependenttranscriptional regulator, which in turn, plays a significant role in the development ofbreast cancer. This study was conducted to find if there is an association betweengenetic polymorphisms in the ER-α gene and breast cancer in Egyptian females andits relation to the age of menarche and menopause. A total of 50 breast cancerEgyptian women and 25 age-matched healthy controls were involved in the study.PvuII and XbaI polymorphisms of ER-α gene were genotyped by polymerase chainreaction restriction fragment length polymorphism. Pp/pp genotypes were found in84% of patients and in 56% of controls; and the homozygous wild PP genotype wasfound in 16% of patients, and 44% of controls. There was highly significant increasein the risk of breast cancer with the presence of PvuII restriction site (Pp/ppgenotypes) compared with absence of restriction site (PP genotype) (P = 0.008).There was statistically significant decrease in the age of menarche (P = 0.021) andinsignificant differences in the age of menopause of all participant women withpresence of PvuII restriction site. Xx/xx genotypes were found in 84% of patients andin 76% of controls; and XX genotype was found in 16% of patients and in 24% ofcontrols. There was insignificant difference in genotype frequency of the ER-α XbaIpolymorphism between patients and controls (P = 0.157). There was statistically veryhighly significant decrease in the age of menarche (P<0.001) and insignificantdifferences in the age of menopause of all participant women with presence of XbaIrestriction site. From the present study, it could be concluded that geneticpolymorphisms in the ER-α gene may play a role in the etiology of breast cancer inEgyptian women and may be a genetic determinants of the age of menarche.