Genetic Polymorphisms as Predictors of Breast Cancer Risk

Genetic alterations are important drivers of breast cancer development. Rare, high penetrance mutations, including BRCA1 and BRCA2, account for a minority of breast cancer cases. Recent advances in genomic sequencing technologies have aided the search for additional genetic modifiers of breast cancer risk. An increasing number of risk-associated single nucleotide polymorphisms (SNPs) are being identified. These SNPs are relatively common in the studied populations, and while they generally confer a small increase in risk individually, they may act in combination to alter risk more substantially. This review synthesizes the current understanding of these genetic polymorphisms and breast cancer risk, and discusses experiences and challenges with implementing them into existing risk models and into clinical practice. As additional SNPs are discovered and risk estimates are refined, the aim will be to use this information to guide personalized decisions around managing risk, and to deepen our understanding of breast carcinogenesis.