Prospective evaluation of BRCA mutations in a large triple-negative breast cancer (TNBC) registry: Implications for germline testing.

1026 Background: Although current NCCN guidelines recommend genetic testing (GT) for all TNBC patients aged <60 years (regardless of family history) however due to the lack of prospective information on prevalence of mutations in unselected TNBC patients, these guidelines have not been widely adopted by clinicians and insurance carriers (including Medicare). Data on BRCA mutations from unselected TNBC cohorts are lacking. Aims: In a large TNBC registry, to prospectively determine the 1) prevalence of germline BRCA mutations and 2) validity of current NCCN guidelines for GT. Methods: Patients with stage I-III TNBC presenting for treatment at an academic and surrounding community practices were approached for participation in a prospective registry. All patients underwent comprehensive BRACAnalysis (Myriad). Detailed FH was collected. Mutation prevalence in the entire cohort and in subgroups stratified by FH and age were calculated. A significant family history (SFH) was defined as 1st-/2nd-degree relatives...