Comparing Prognosis for BRCA1 , BRCA2 , and Non-BRCA Breast Cancer.

Simple Summary: Approximately 10% of breast cancer (BC) cases are hereditary, and germline pathogenic variants in BRCA1 and BRCA2 genes account for 20% of familial BC cases. Long-term follow-up data related to the prognosis and survival of either BRCA1 or BRCA2 BC patients are conflicting. The aim of this study is to report the analysis of our cohort of BRCA1/2 BC patients included in prospective follow-up after genetic testing. We compared clinicopathological characteristics and prognosis between BC patients with BRCA1 and BRCA2 and a control group without germline PV (BRCA-wt). The presence of BRCA mutation confers a higher risk of relapse and death in patients with BC in the Portuguese population. Prophylactic mastectomy and preventive salpingo-oophorectomy confer lower incidence of relapse and longer median invasive disease-free survival and overall survival, respectively. Background: Germline pathogenic variants (PV) in BRCA1 and BRCA2 genes, which account for 20% of familial breast cancer (BC) cases, are highly penetrant and are associated with Hereditary Breast/Ovarian Cancer Syndrome. Previous studies, mostly including higher numbers of BRCA1 BC patients, yielded conflicting results regarding BRCA1/2 BC outcomes. In the Portuguese population, BRCA2 BC is diagnosed more frequently than BRCA1 BC. We aimed to compare clinicopathological characteristics and prognosis between BC patients with BRCA1 and BRCA2 mutations and a control group without germline PV (BRCA-wt). Furthermore, we explored the frequency and outcomes of risk-reducing surgeries in BRCA-mutated patients. Methods: Prospective follow-up was proposed for patients with a diagnosed BRCA1/2 PV. For this study, a matched control group (by age at diagnosis, by decade, and by stage at diagnosis) included BC patients without germline PV. We compared overall survival (OS) and invasive disease-free survival (iDFS) within the three groups, and the use of risk-reducing surgeries among the BRCA cohort. Results: For a mean follow-up time of 113.0 months, BRCA-wt patients showed longer time to recurrence (p = 0.002) and longer OS (p < 0.001). Among patients with BRCA mutations, no statistical differences were found, although patients with BRCA2 BC had longer iDFS and OS. Uptake of risk-reducing surgeries (contralateral prophylactic mastectomy and salpingo-oophorectomy) were negative predictors of invasive disease and death, respectively. Conclusions: Testing positive for a BRCA PV is associated with a higher risk of relapse and death in patients with BC in the Portuguese population. Risk-reducing mastectomy and salpingo-oophorectomy were associated with lower incidence of relapse and longer median iDFS and OS, respectively. [ABSTRACT FROM AUTHOR]