ABSTRACT
Polymorphisms of hormone receptor genes have been linked to modifications in reproductive factors and to an increased risk of breast cancer (BC). In the present study, we have determined the allelic and genotypic frequencies of the ERα-397 PvuII C/T, ERα-351 XbaI A/G and PGR PROGINS polymorphisms and investigated their relationship with mammographic density, body mass index (BMI) and other risk factors for BC. A consecutive and unselected sample of 750 Brazilian BC-unaffected women enrolled in a mammography screening program was recruited. The distribution of PGR PROGINS genotypic frequencies was 72.5, 25.5 and 2.0% for A1A1, A1A2 and A2A2, respectively, which was equivalent to that encountered in other studies with healthy women. The distribution of ERα genotypes was: ERα-397 PvuII C/T: 32.3% TT, 47.5% TC, and 20.2% CC; ERα-351 XbaI A/G: 46.3% AA, 41.7% AG and 12.0% GG. ERα haplotypes were 53.5% PX, 14.3% Px, 0.3% pX, and 32.0% px. These were significantly different from most previously published reports worldwide (P < 0.05). Overall, the PGR PROGINS genotypes A2A2 and A1A2 were associated with fatty and moderately fatty breast tissue. The same genotypes were also associated with a high BMI in postmenopausal women. In addition, the ERα-351 XbaI GG genotype was associated with menarche ≥12 years (P = 0.02). ERα and PGR polymorphisms have a phenotypic effect and may play an important role in BC risk determination. Finally, if confirmed in BC patients, these associations could have important implications for mammographic screening and strategies and may be helpful to identify women at higher risk for the disease.
Subject(s)
Adult , Aged , Female , Humans , Middle Aged , Breast Neoplasms/genetics , Deoxyribonucleases, Type II Site-Specific/genetics , Estrogen Receptor alpha/genetics , Genetic Predisposition to Disease , Polymorphism, Genetic/genetics , Receptors, Progesterone/genetics , Body Mass Index , Brazil , Breast Neoplasms/diagnosis , Gene Frequency , Genotype , Mammary Glands, Human/abnormalities , Prevalence , Risk FactorsABSTRACT
OBJECTIVE: This study aimed to determine the frequency of the PROGINS polymorphism in women with endometriosis-associated infertility, in infertile women without endometriosis and in controls. INTRODUCTION: The human progesterone receptor gene has two isoforms that modulate the biological action of progesterone: isoform A, which is capable of inhibiting the activation of the estrogen receptors, and isoform B, which has the capacity to activate the estrogen receptors. Several polymorphisms have been described for this gene, among which one stands out: a polymorphism named PROGINS, which has been speculated to be related to the genesis of endometriosis by several studies with conflicting results. METHODS: This was a prospective study that included 148 patients with endometriosis-associated infertility, 50 idiopathic infertile patients and 179 fertile women as controls. The PROGINS polymorphism was studied by PCR. RESULTS: Genotypes P1P1, P1P2 and P2P2 (P2 representing the PROGINS polymorphism) of the progesterone receptor gene presented frequencies of 93.9 percent, 5.4 percent and 0.7 percent, respectively, in the women with endometriosis-associated infertility (p=0.2101, OR=0.51, 95 percent CI=0.24-1.09); 94.4 percent, 4.2 percent and 1.4 percent, respectively, in the patients with minimal/mild endometriosis (p=0.2725, OR=0.53, 95 percent CI=0.20-1.43); 93.5 percent, 6.5 percent and 0 percent, respectively, among the patients with moderate/severe endometriosis (p=0.3679, OR=0.49, 95 percent CI=0.18-1.31); 86.0 percent, 14.0 percent and 0 percent, respectively, in idiopathic infertile women (p=0.8146, OR=1.10, 95 percent CI=0.46-2.63); and 88.3 percent, 10.6 percent and 1.1 percent, respectively, in the control group. CONCLUSION: The data suggest that PROGINS is not related either to endometriosis-associated infertility or to idiopathic infertility in the population studied.