Prevalence of BRCA1 and BRCA2 mutations in triple negative breast cancer

Triple negative breast cancer (TNBC) is a term that reflects lack of immunostaining for oestrogen, progesterone, and HER2 receptors. It is a relatively uncommon subgroup of breast cancers, accounting for approximately 15% of all types, and overlaps substantially with basal tumours (defined by gene expression pattern) that are the predominant tumour that develops in BRCA1 mutation carriers.1 TNBCs usually have a worse prognosis and no clear options for receptor targeted treatment.2 The recent development of drugs that target the homologous recombination repair deficiency typical of BRCA-null cancer cells has led to an increased referral of women who have developed TNBC to genetic services for (rapid) genetic testing.3 We have tested 63 isolated cases of TNBC