Risk of contralateral breast cancer amongst BRCA1/2 mutation carriers

Women harbouring a deleterious mutation in the high penetrance BRCA1/2 genes have a lifetime risk of up to 85% of developing breast cancer (1). Once diagnosed, they have a significant risk of developing a contralateral breast cancer—approximately 2–3% per year. This risk persists for up to 30 years following an initial breast cancer diagnosis (2).