Outcome of ovarian cancer after breast cancer in BRCA1 and BRCA2 mutation carriers

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.