- Among patients with germline BRCA+ metastatic breast cancer (mBCa), OS is worse for triple-negative breast cancer (TNBC) than hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative mBCa (hereinafter referred to as the TNBC and the HR+ groups, respectively).
- Testing for germline BRCA was low (16.7%) among the larger cohort of mBCa patients from which the TNBC and HR+ groups were drawn.
Why this matters
- Patients should be informed of prognosis to make informed decisions about care.
- Improved testing for germline BRCA mutations is needed, given the availability of new second-line mBCa treatments, olaparib and talazoparib (approved after this study was performed).
- Real-world retrospective cohort of 12,021 mBCa patients in the Flatiron Health electronic health record database (2011-2018); 1.9% had germline BRCA mutations (HR+ group, n=165; TNBC group, n=64).
- Funding: Pfizer Inc.
- Only 16.7% of patients were tested for BRCA mutations; 11.4% of these tested positive.
- Median OS in the TNBC group was 23.4 (95% CI, 14.9-34.5) months vs 38.0 (95% CI, 30.8-42.9) months in the HR+ group.
- The HR+ group had 55% better OS (HR, 0.45; P=.002).
- Most common first-line treatment post-mBCa diagnosis was letrozole (8%) for the HR+ group and capecitabine (14%) for the TNBC group.
- Observational design.