Awareness and availability of routine germline BRCA1/2 (gBRCA1/2) mutation testing in patients with Advanced Breast Cancer (ABC) in the outpatient oncology setting in Germany
Lux M.P.1,2,3, Decker T.4, Runkel E.D.5, Niyazov A.6, Quek R.G.W.7, Glastetter E.5, Marschner N.8, Harbeck N.9
1Kooperatives Brustzentrum Paderborn, Paderborn, Deutschland, 2Frauen- und Kinderklinik St. Louise, Paderborn, Deutschland, 3St. Josefs-Krankenhaus, Salzkotten, Deutschland, 4Onkologie Ravensburg, Ravensburg, Deutschland, 5Pfizer Pharma GmbH, Berlin, Deutschland, 6Pfizer Inc., New York, Vereinigte Staaten von Amerika, 7Pfizer Inc., San Francisco, Vereinigte Staaten von Amerika, 8iOMEDICO AG, Freiburg, Deutschland, 9Brustzentrum, Frauenklinik der Universität München (LMU), München, Deutschland

Introduction: We investigated clinical practice, awareness, and availability of routine gBRCA1/2 testing in German outpatient oncology setting.
Material: 23-item online survey.
Methods: Completed by 50 office-based oncologists (medical/gynecologic), October 2019-February 2020.
Results: Known family history (FH) of gBRCA1/2-related cancer(s) and hormone receptor status influences gBRCA1/2 testing (Table). Most oncologists routinely test ABC patients with triple-negative breast cancer (TNBC) independent of FH; only reason for not testing TNBC patients (n=3) was reimbursement difficulties. Testing rates for HR+/HER2- ABC patients were generally lower and depended on FH. Reasons for not testing HR+/HER2- ABC patients (n; with FH 7, without 33): available therapy alternatives [rate (%); with FH 100.0, without 54.5], reimbursement difficulties [rate (%); with FH 28.6, without 24.2] or other [rate (%); with FH 0, without 24.2]. Other factors included guideline recommendations and age at BC onset. Test turnaround time [median (range); 4.0 (1.0-21.0) weeks] and availability of genetic counseling influenced when oncologists routinely initiate gBRCA1/2 testing (46.0%; 36.0%, respectively). Most oncologists reported access to gBRCA1/2 testing as satisfactory (30.0%) or good (36.0%).
Conclusion: gBRCA1/2 testing seems established in Germany's outpatient oncology setting. Opportunities exist to improve testing of HR+ ABC patients without family history given gBRCA1/2-targeted therapy options. Funding: Pfizer.

ABC Subtype ABC patients WITH known family history of gBRCA1/2-related cancer(s): Testing Rate in % (n/N) ABC patients WITHOUT known family history of gBRCA1/2-related cancer(s): Testing Rate in % (n/N)
TNBC 98.0 (49/50) 92.0 (46/50)
HR+/HER2- 82.0 (41/50) 30.0 (15/50)
HR+/HER2+ 76.0 (38/50) 10.0 (5/50)
HR-/HER2+ 82.0 (41/50) 16.0 (8/50)
[gBRCA1/2 testing rates [% (n/N)] in ABC patients by subtype and family history (n=number of physicians who replied yes; N=number of physicians asked)]