TY - JOUR T1 - Prevalence of <em>BRCA1</em> and <em>BRCA2</em> mutations in triple negative breast cancer JF - Journal of Medical Genetics JO - J Med Genet SP - 520 LP - 522 DO - 10.1136/jmedgenet-2011-100006 VL - 48 IS - 8 AU - D G Evans AU - A Howell AU - D Ward AU - F Lalloo AU - J L Jones AU - D M Eccles Y1 - 2011/08/01 UR - http://jmg.bmj.com/content/48/8/520.abstract N2 - 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 &lt;41 years and only eight (12.7%) had a BRCA1 mutation.The decision to test women affected with breast cancer for BRCA mutations has traditionally been based on clinical utility (clarifying the future risks of contralateral breast cancer/ovarian cancer for the index case). Equally importantly the result may help develop a genetic test for the wider family facilitating their risk assessment and management. However, recently the utility of testing to the oncologist treating the cancer in the index case has come sharply into focus with the advent of treatments such as the PARP (poly ADP ribose polymerase) inhibitors.3 Despite the fact that treatment with PARP inhibitors is still only available through research trials, our experience in the genetic clinic is of unrealistically high expectations about the likelihood of an underlying BRCA1 mutation … ER -