Prediction of pathogenic mutations in patients with early-onset breast cancer by family history

Summary We aimed to assess frequency and penetrance of BRCA1, BRCA2 , and TP53 mutations in women diagnosed with breast cancer aged 30 years or younger, and then correlate this frequency with family history. 17 of 36 familial cases had a BRCA1, BRCA2 , or TP53 mutation, compared with three of 63 non-familial cases. The calculated population frequency of TP53 mutations was one in 5000, substantially greater than previous estimates. This finding underlines the importance of accurate elucidation of a family history from young women diagnosed with breast cancer. Establishment of family history could help with development of patient-specific management and tumour surveillance protocols.