BRCA testing rates, treatment patterns and outcomes were compared based on BRCA mutation status in HER2- adult women with ABC.
Oncologists extracted data from patient charts in adult women with HER2- ABC across the US and France, Germany, Italy, Spain and the United Kingdom (EU5) via the Adelphi Advanced Breast Cancer Disease Specific Program. Data drawn from 2015 and 2017 were merged across common variables. Patients were categorized into three mutually exclusive cohorts; BRCA mutations (BRCAm), wild type (BRCAwt), and unknown status (BRCAunk). Treatments received and 1st line duration of therapy was compared between BRCAm and BRCAwt using Fisher exact, Mann-Whitney tests, and t-tests.
The study included 6,161 adult women with HER2- ABC (4,611 hormone receptor positive [HR+/HER2-], 1,415 triple negative breast cancer [TNBC], 135 unknown hormone status). Overall, 28% of patients received ≥1 BRCA test at any point in their lifetime (23% HR+/HER2-, 41% TNBC). 235/6,161 (4%) patients were identified as BRCAm, 1,025/6,161 (17%) as BRCAwt, and 4,901/6,161 (80%) as BRCAunk. Within the HR+/HER2- cohort, patients with BRCAm were more likely to receive 1st line chemotherapy compared to BRCAwt (65% vs 49%; P = 0.005) and less likely to receive endocrine +/- targeted therapies (33% vs 49%; P = 0.003). TNBC treatments consisted primarily of chemotherapy and were similar between BRCAm vs. BRCAwt, (89% vs. 91%; P = 0.545). Mean duration among patients who completed 1st line treatment was numerically shorter for patients with BRCAm [Table].
1st line duration of therapy (mean months [SD]) based on BRCA status Includes HR+, TNBC and HR unknown patients.BRCAm (n = 34) BRCAwt (n = 282) P value HR+/HER2- 7.8[10.0] 11.4 [5.5] 0.648 TNBC 6.4 [6.1] 5.0 [2.9] 0.933 HER2-a 6.6 [7.0] 9.0 [13.4] 0.408
In this study of adult women with HER2- ABC, low BRCA testing rates were observed. Patients with BRCAm were significantly more likely to utilize chemotherapy relative to BRCAwt. Mean duration of 1st line therapy was numerically lower among patients with BRCAm. With the advent of new treatment options, additional studies are warranted to validate these findings.
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A. Niyazov: Employee, stockholder: Pfizer; R.G.W. Quek: Employee, ownership interest: Pfizer. All other authors have declared no conflicts of interest.