Abstract: | Background: It is unknown whether a history of breast cancer (BC) affects the outcome of BRCA1/2-associated epithelial ovarian cancer (EOC). This was investigated in the current analysis.Methods: We included 386 BRCA1/2-associated EOC patients diagnosed between 1980 and 2015. Progression-free survival (PFS), progression-free interval (PFI), overall survival (OS) and ovarian cancer-specific survival (OCSS) were compared between EOC patients with and without previous BC.Results: BRCA-associated EOC patients with, vs without, a BC history had a significantly worse PFS and PFI (multivariate hazard ratio (HRmult) 1.47; 95% confidence interval (CI) 1.03–2.08 and HRmult 1.43; 95% CI 1.01–2.03), and a non-significantly worse OS (HRmult 1.15; 95% CI 0.84–1.57) and OCSS (HRmult 1.18; 95% CI 0.85–1.62). Ovarian cancer-specific survival was significantly worse for the subgroup treated with adjuvant chemotherapy for BC (HRmult 1.99; 95% CI 1.21–3.31).Conclusions: Our results suggest that BRCA1/2-associated EOC patients with a previous BC have a worse outcome than EOC patients without BC, especially when treated with adjuvant chemotherapy. |