The polygenic risk score in the breast cancer treatment

Breast cancer (BC) remains the most common cause of death in women worldwide, but advances in science have allowed earlier diagnosis and more comprehensive treatment. This review highlights the impact of extensive molecular genetic testing in assessing the risk of BC susceptibility, as well as possible responses to chemotherapy and radiotherapy. Studies in the literature show that several Single Nucleotide Polymorphisms (SNPs) of genes involved in molecular pathways may become predictors of the risk of developing BC. For example, SNPs in genes such as RAD51 and XRCC3 , already known to be linked with high BC susceptibility, were also correlated with a different response to radiotherapy and related adverse effects. In addition, the SNP ESR1 PvuII (rs2234693), on the ESR1 gene, has been associated with a poor prognosis in advanced BC, but can be a good predictor of the therapeutic effect of hormonal treatment. Therefore, SNPs can be considered as possible new biomarkers for BC risk and prognosis. In this view, it is important to evaluate Polygenic Risk Score, an essential component for accurate BC risk prediction, which may potentially improve screening and prevention strategies. Bioinformatics tools are available to calculate polygenic risk by assessing the presence of SNPs and patients’ family and personal history. This represents an important step forward in the era of personalized medicine for BC.