BRCA1/2 Mutation Testing in Patients with HER2-Negative Advanced Breast Cancer: Real-World Data from the United States, Europe, and Israel

Abstract

Poly(adenosine diphosphate-ribose) polymerase inhibitors are approved to treat patients harboring a germline breast cancer susceptibility gene 1 or 2 mutation (BRCA1/2mut) with human epidermal growth factor receptor 2—negative (HER2−) advanced breast cancer (ABC). This study evaluated differences in patient demographics, clinical characteristics, and BRCA1/2mut testing within the United States (US), European Union 4 (EU4; France, Germany, Italy, and Spain), and Israel in a real-world population of patients with HER2− ABC. Oncologists provided chart data from eligible patients from October 2019 through March 2020. In the US, EU4, and Israel, 73%, 42%, and 99% of patients were tested for BRCA1/2mut, respectively. In the US and the EU4, patients who were not tested versus tested for BRCA1/2mut were more likely to have hormone receptor—positive (HR+)/HER2− ABC (US, 94% vs. 74%, p < 0.001; EU4, 96% vs. 78%, p < 0.001), less likely to have a known family history of BRCA1/2-related cancer (US, 6% vs. 19%, p = 0.002; EU4, 10% vs. 28%, p < 0.001), and were older (US, 68.9 vs. 62.5 years, p < 0.001; EU4, 66.7 vs. 58.0 years, p < 0.001). Among tested patients, genetic counseling was received by 45%, 53%, and 98% with triple-negative breast cancer, and 36%, 36%, and 98% with HR+/HER2− ABC in the US, EU4, and Israel, respectively. Efforts should be made to improve BRCA1/2 testing rates in the US and Europe.

Progress and prospects in research and clinical practice of hormone receptor-positive, HER-2-negative breast cancer with BRCA1/2 mutations

“…Since then, the frequency of BRCAm testing has increased [ 40 ]. A recent study assessed the rate of BRCA1/2m testing in HER2- advanced BC in the United States, Israel, and Europe from October 2019 to March 2020 [ 41 ]. The rates of gBRCA1/2m testing are still relatively low among the HR+/HER2- subgroups, although BRCA1/2m testing has increased.…”

“…Since then, the frequency of BRCAm testing has increased [40]. A recent study assessed the rate of BRCA1/2m testing in HER2-advanced BC in the United States, Israel, and Europe from October 2019 to March 2020 [41].…”

Editorial for the Special Issue “Breast Cancer—Therapeutic Challenges, Research Strategies and Novel Diagnostics”

“…In the US and Europe, patients who were not tested versus those who were tested were older, more likely to have HR+/HER2− aBC than TNBC and less likely to have a known family history of BRCA1/2 -related cancer. Efforts should be made to improve BRCA1/2 testing rates in affected countries [ 7 ].…”