Abstract P6-08-10: Physician practice settings and BRCA1/2 testing rates in HER2- advanced breast cancer (ABC): Results from the European component of a multi-country real-world study
Authors: Lux Michael P. , Lewis Katie , Rider Alex , Niyazov Alexander 
Published: March 2020

Background: Mutations in breast cancer susceptibility genes 1 or 2 (BRCA1/2) are known risk factors for developing cancer, especially for breast cancer (BC) and ovarian cancer (OC). Recently, BC guidelines have expanded the eligibility criteria for BRCA1/2 testing. This study assessed somatic and/or germline BRCA1/2 testing rates in human epidermal growth factor receptor 2-negative (HER2-) adult women with advanced breast cancer (ABC) in Germany, Italy, France, Spain, and the United Kingdom (EU5). Methods: Patient (pt.) demographics/clinical characteristics in adult women with HER2- ABC were abstracted from medical charts by oncologists in EU5 countries via Adelphi Advanced Breast Cancer Disease Specific Program. Information of oncologist practice setting (academic or community) was also collected. Data collected from 2 different years (2015 and 2017) were merged across common variables (e.g. age, hormone receptor status, BRCA1/2 testing rates, BRCA status). Differences in pt. demographics/characteristics among BRCA1/2 tested pts. by physician practice was analyzed via t-test and Fisher Exact tests. Analyses of BRCA1/2 testing rates were stratified by practice setting and analyzed by Fisher Exact tests. Results: Overall, 4,876 records were provided by 742 oncologists. The mean age was 63.6 yrs; 75% hormone receptor (HR)+/HER2-, 23% triple negative breast cancer (TNBC), 2% unknown HR status. Across all the EU5 countries, the mean BRCA1/2 testing rate was 21%. Testing rates varied based on physician practice setting (Table 1) across EU5 countries. Pts. who were BRCA1/2 tested and currently consulting with oncologists in academic medical centers were significantly younger and more likely to be currently employed than those consulting in non-academic centers [mean age 56.4 vs 60.0 (p&lt;0.001); proportion employed 28% vs 17% (p&lt;0.001)]. Pts. with a known family history of BC or OC were more likely to be BRCA1/2 tested when currently consulting with oncologists based in academic medical centers than non-academic medical centers [45% vs 37% (p=0.071)]. Conclusions: In this real-world study of adult women with HER2- ABC, low BRCA1/2 testing rates were observed in general, with variation in testing rates across different EU5 countries. Significant differences in BRCA1/2 testing rates were observed among academic vs non-academic types of physician practices in Italy, France and the UK. With the broadening of BRCA1/2 testing eligibility criteria in BC guidelines, opportunities exist to increase BRCA1/2 testing in both EU5 academic and non-academic physician settings, particularly in the UK.

Funding: Pfizer Inc.

Table. BRCA1/2 testing rates by physician practice settingCountryAcademicNon-academicP ValueGermany Pts tested No. (%)N=452 146 (32)N=538 149 (28)0.125Italy Pts tested No. (%)N=411 81 (20)N=528 145 (27)0.007France Pts tested No. (%)N=601 141 (23)N=403 55 (14)&lt;0.001Spain Pts tested No. (%)N=835 161 (19)N=146 40 (22)0.477UK Pts tested No. (%)N=819 122 (15)N=95 6 (6)0.019

Citation Format: Michael P. Lux, Katie Lewis, Alex Rider, Alexander Niyazov. Physician practice settings and BRCA1/2 testing rates in HER2- advanced breast cancer (ABC): Results from the European component of a multi-country real-world study [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-08-10.