Background: Genetic variations in oxidative stress-related genes may alter the coded protein level and impact the pathogenesis of breast cancer.
Methods: The current study investigated the associations of functional single nucleotide polymorphisms in the NFE2L2, HMOX1, P21, TXNRD2, and ATF3 genes with the early-stage breast cancer clinicopathological characteristics and disease-free survival, metastasis-free survival, and overall survival. A total of 202 Eastern European (Lithuanian) women with primary I-II stage breast cancer were involved. Genotyping of the single nucleotide polymorphisms was performed using TaqMan single nucleotide polymorphisms genotyping assays.
Results: The CA+AA genotypes of P21 rs1801270 were significantly less frequent in patients with lymph node metastasis and larger tumor size (P=0.041 and P=0.022, respectively). The TT genotype in ATF3 rs3125289 had significantly lower risk of estrogen receptor (ER), progesterone receptor (PR) negative, and human epidermal growth factor receptor 2 (HER2) positive status (P=0.023, P=0.046, and P=0.040, respectively). In both, univariate and multivariate Cox analysis, TXNRD2 rs1139793 GG genotype vs. GA+AA was a negative prognostic factor for disease-free survival (multivariate hazard ratio (HR) 2.248; P=0.025) and overall survival (multivariate HR 2.248; P=0.029). The ATF3 rs11119982 CC genotype in the genotype model was a negative prognostic factor for disease-free survival (multivariate HR 5.878; P=0.006), metastasis-free survival (multivariate HR 4.759; P=0.018), and overall survival (multivariate HR 3.280; P=0.048).
Conclusion: Our findings suggest that P21 rs1801270 is associated with lymph node metastasis and larger tumor size, and ATF3 rs3125289 is associated with ER, PR, and HER2 status. Two potential, novel, early-stage breast cancer survival biomarkers, TXNRD2 rs1139793 and ATF3 rs11119982, were detected. Further investigations are needed to confirm the results of the current study.
Keywords: Breast cancer; HMOX1; NFE2L2; P21; TXNRD2; oxidative-stress; prognosis; single nucleotide polymorphisms.