Significance of the Estrogen Hormone and Single Nucleotide Polymorphisms in the Progression of Breast Cancer among Female

Breast cancer is one of the most frequent types of malignancies among women and is internationally recognized as the main reason for cancer-caused mortality. Most breast tumors are heterogeneous and genetically complicated due to the involvement of several genes. Therefore, it is clinically important to study genetic variants that increase the risk of breast cancer. It is identified that the presence of polymorphisms in genes encoding regulatory hormones is linked to a higher risk of breast cancer. Additionally, circulating estrogen levels are connected to aromatase (CYP19A1) genes, which is a recognized risk factor for breast cancer progression. In this paper, the authors present a review study on the effect of estrogen and its Single Nucleotide Polymorphisms (SNPs) in the occurrence of breast cancer. This review mainly aimed to find out the connection between CYP19A1 gene variations and the risk of breast cancer, as well as its clinical characteristics and prognosis. Due to the highly special activity of the CYP19A1 enzyme in steroid production, suppression of the targeted CYP19A1 is a focused medication for breast cancer patients, which has only minor adverse effects. Numerous clinical trials over the last decade have shown that Aromatase inhibitors (AIs) not only outperform tamoxifen in terms of effectiveness but also have a lower adverse effect profile. The AI is now widely accepted as a routine therapy option for postmenopausal females with Estrogen receptor-positive (ER+) breast cancer. Furthermore, not only dysregulation of gene expression in different genes related to distinguished pathways, such as estrogen metabolism, is essential in the progression of breast cancer but also particular SNPs can play an essential role in particular genes, such as CYP19A1. Different studies have demonstrated that these SNPs can be located in different sites of these genes, which are collected in this review. In a nutshell, more specific clinical trials are required to demonstrate the precise meditative role of anti-estrogen drugs in the treatment of ER+ breast cancer patients. Furthermore, more genotype analyses are needed to confirm the role of SNPs in the progression of breast cancer.