ESR2 gene variants (rs1256049, rs4986938, and rs1256030) and their association with breast cancer risk.

Background: Variants of the estrogen receptor b (ESR2) gene have been associated with different types of cancer. However, these associations have been inconsistent. We genotyped the ESR2 variants (rs1256049, rs4986938, and rs1256030) in breast cancer (BC) patients and in healthy women. Results: The variants rs1256049 and rs4986938 in the ESR2 gene were not associated with risk susceptibility in BC patients. However, the rs1256030 variant had an association as a risk factor for BC patients when compared with controls and BC patients for the TT genotype (odds ratio (OR) 1.86, 95% confidence intervals (CI) [1.05-3.28], p = 0.042). In addition, differences were observed in patients and controls carrying the TT genotype under 50 years of age (OR 1.85, 95% CI [1.05-3.27], p = 0.043). Thus, evident differences showed the rs1256030 variant in patients with TT, TC, and TC+TT genotypes with: (1) Stage IV (OR 1.60, 95% CI [1.06-2.54], p = 0.033), and (2) Luminal A (OR 1.60, 95% CI [0.47-0.21], p = 0.041), as well as in BC carriers of the TT genotype with indices of cellular proliferative (Ki-67) elevated (>20%) and overweight (OR 1.67, 95% CI [0.85-3.28], p = 0.041), respectively. In BC HER2 with lymph node metastasis, the TT genotype was a protective factor (OR 0.38, 95% CI [0.18-0.78], p = 0.005). The identification of haplotypes included two common GAT as risk factors (OR 3.1, 95% CI [1.31-7.72], p = 0.011) and GGC as a protective factor (OR 0.7, 95% CI [0.60-0.97], p = 0.034). The haplogenotype GGGATC was a risk factor (OR 2.5, 95% CI [1.28-5.0], p = 0.008). Conclusion: The variant rs1256030 (TT) of the ESR2 gene and haplotype GAT were associated with susceptibility to BC as risk factors in this sample from the Mexican population.

Association of the Del1518 Promoter (rs3730485) Polymorphism in the MDM2 Gene with Breast Cancer in a Mexican Population.

INTRODUCTION: The MDM2 gene plays an important role in tumorigenesis. The data on the Del1518 promoter polymorphism in the MDM2 gene have revealed associations with cancer. MATERIAL AND METHODS: We examined the role of the MDM2 Del1518 polymorphism through a comparison of the genotypes of 345 healthy Mexican women with those of 742 Mexican women with breast cancer (BC). RESULTS: The genotype frequencies of the MDM2 Del1518 polymorphism in controls and patients with BC were 64% and 55.5% for ins/ins, 32% and 31.5% for ins/del, and 4% and 13% for del/del, respectively. The obtained odds ratio (OR) was 3.26, with a 95% confidence interval (95% CI) of 1.86-5.72 and p=0.0001, for the del/del genotype. An association was evident when we examined the distribution of the del/del genotype in patients with elevated levels of transaminase SGPT (OR=2.268; 95% CI=1.40-3.65; p=0.0001). Additionally, we observed an association of the genotypes del/del - ins/del in menopausal patients with BC with the following characteristics: tobacco consumption (OR = 1.93, 95% CI = 1.07-3.4, p=0.025), pregnancy loss (OR=2.44, 95% CI=1.37-4.35, p=0.0024), obesity (I-IV) (OR=1.8, 95% CI=1.1-2.9, p= 0.018), and elevated serum glucose levels (OR=3.72, 95% CI=2.0-6.85, p=0.0001). CONCLUSIONS: The MDM2 Del1518 polymorphism was associated with BC susceptibility, particularly in menopausal patients with BC who reported tobacco consumption, pregnancy loss, obesity and high glucose levels in the analyzed Mexican population.