Effect of BRCA germline mutations on breast cancer prognosis

BACKGROUND The contribution of BRCA germline mutational status to breast cancer patients' prognosis is unclear. We aimed to systematically review and perform meta-analysis of the available evidence of effects of BRCA germline mutations on multiple survival outcomes of breast cancer patients as a whole and in specific subgroups of interest, including those with triple negative breast cancer, those with Ashkenazi Jewish ancestry, and patients with stage I-III disease. METHODS Sixty studies met all inclusion criteria and were considered for this meta-analysis. These studies involved 105,220 breast cancer patients, whose 3588 (3.4%) were BRCA mutations carriers. The associations between BRCA genes mutational status and overall survival (OS), breast cancer-specific survival (BCSS), recurrence-free survival (RFS), and distant metastasis-free survival (DMFS) were evaluated using random-effect models. RESULTS BRCA1 mutation carriers have worse OS than BRCA-negative/sporadic cases (hazard ratio, HR 1.30, 95% CI: 1.11-1.52) and worse BCSS than sporadic/BRCA-negative cases among patients with stage I-III breast cancer (HR 1.45, 95% CI: 1.01-2.07). BRCA2 mutation carriers have worse BCSS than sporadic/BRCA-negative cases (HR 1.29, 95% CI: 1.03-1.62), although they have similar OS. Among triple negative breast cancer, BRCA1/2 mutations carriers had better OS than BRCA-negative counterpart (HR 0.49, 95% CI: 0.26-0.92). Among Ashkenazi Jewish women, BRCA1/2 mutations carriers presented higher risk of death from breast cancer (HR 1.44, 95% CI: 1.05-1.97) and of distant metastases (HR 1.82, 95% CI: 1.05-3.16) than sporadic/BRCA-negative patients. CONCLUSION Our results support the evaluation of BRCA mutational status in patients with high risk of harboring BRCA germline mutations to better define the prognosis of breast cancer in these patients.