Background: Findings show that 5-10 % of women with a diagnosis of breast cancer (BCa) have actionable genetic mutations. The National Comprehensive Cancer Network guidelines for testing to detect BRCA1/2 mutations include personal history (PH) variables such as age of 45 years or younger and a family history (FH) variables. Rates of FH documentation and overall rates of appropriate referral for genetic testing are low, ranging from about 30 to 60 %. The authors hypothesized that an upfront FH documentation and inclusion of a genetics counselor in a multidisciplinary clinic (MDC) setting would increase rates of appropriate referral for genetic testing.
Methods: The study enrolled 609 consecutive women with non-metastatic BCa seen in consultation between June 2012 and December 2015 at a multidisciplinary clinic. Rates of FH documentation and referral for genetic testing to detect BRCA1/2 mutations were assessed before and after inclusion of a genetic counselor in the MDC.
Results: The rates of FH documentation and appropriate referral were 100 and 89 %, respectively. Half (50 %) of the patients had only FH-based indications for testing. All the patients with PH-based indications were referred. The inclusion of a genetic counselor significantly increased appropriate referral rates among those with only FH-based indications (62 vs. 92 %) and overall (80 vs. 96 %) (p < 0.0001 for both). Among the 12 % of the patients with actionable mutations, 60 % were 45 years of age or younger, whereas 30 % had only FH-based testing indications.
Conclusions: This report shows substantially higher FH documentation and appropriate genetic testing rates than prior reports. Many patients with indications for genetic testing may have only FH-based indications for testing, and this subset may account for the sizable proportion of patients with newly diagnosed BCa who have actionable mutations.