Objectives It has been suggested that women with BRCA mutation and incidentally detected occult invasive ovarian cancer (OOC) diagnosed at the time of risk-reducing salpingo-oophorectomy (RRSO) have poorer prognosis than would be expected per stage. We sought to evaluate the prevalence and clinical outcomes of BRCA-mutated patients with OOC undergoing RRSO in a tertiary referral center.

Methods Patients with a BRCA mutation who underwent RRSO from 01/2005–05/2017 were identified, and records reviewed. Women with preoperative suspicion for malignancy (e.g. adnexal mass or elevated CA125) were excluded.

Results 532 patients with BRCA mutation undergoing RRSO were identified. 26 (4.8%) had OOC. Median age was 55 years (range 42–75). 15(58%) patients had BRCA1, 9(34%) BRCA2, and 2(8%) had a mutation in both genes. All OOCs were high-grade serous: 10 (38%) Stage I, 8 (31%) Stage II, 8(31%) Stage III. 24(92%) patients received adjuvant platinum/taxane therapy. Of Stage III patients, 4 (50%) had microscopic disease only, 4 (50%) had suspicious intraoperative findings. At a median follow-up of 53.6 mos (7–164) no Stage I patients have recurred; 1(13%) Stage II patient and 5(63%) Stage III patients have recurred. Five-year PFS was 74% (95%CI 44–87.7%); median PFS for the cohort was 129 months (35.9-not estimable). Five-year DSS was 96.2% (95%CI 73.9–99.4%), median DSS not reached.

Conclusions Consistent with prior reports, almost 5% of patients had OOC detected at time of RRSO. In contrast to prior data, the majority had early-stage disease with excellent PFS and DSS outcomes as would be expected per stage.