Real-world multi-country study of BRCA1/2 mutation testing among adult women with HER2-negative advanced breast cancer.

Aim: We assessed real-world patient demographics and BRCA1/2 mutation testing rates among adult women with HER2-negative advanced breast cancer (ABC). Methods: Oncologists across the USA and in France, Germany, Italy, Spain and the UK provided medical chart data in 2015 and 2017. Results: Overall, 28% of patients received BRCA1/2 mutation testing. Untested patients were more likely to be aged ≥45 years, have hormone receptor-positive/HER2-negative ABC and have no known family history of breast/ovarian cancer. BRCA1/2 mutation testing rates were significantly lower in the European countries, women aged ≥45 years, women without a known family history of breast/ovarian cancer, and women with hormone receptor-positive/HER2-negative ABC versus advanced triple-negative breast cancer. Conclusion: BRCA1/2 mutation testing rates were low, and disparities were observed in patient characteristics among BRCA1/2 mutation-tested versus untested patients.