BACKGROUND: Germline pathogenic variants (PV) in and 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 BC patients, yielded conflicting results regarding BC outcomes. In the Portuguese population, BC is diagnosed more frequently than BC. We aimed to compare clinicopathological characteristics and prognosis between BC patients with and mutations and a control group without germline PV (). Furthermore, we explored the frequency and outcomes of risk-reducing surgeries in -mutated patients. METHODS: Prospective follow-up was proposed for patients with a diagnosed 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 cohort. RESULTS: For a mean follow-up time of 113.0 months, -wt patients showed longer time to recurrence ( = 0.002) and longer OS ( < 0.001). Among patients with mutations, no statistical differences were found, although patients with 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 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.