Abstract 856P
Background
Women with germ-line BRCA1 or BRCA2 mutations have an increased risk of ovarian cancer (OC) when compared with the general population. RRBSO is highly effective in reducing OC risk and overall mortality. The Royal Marsden (RM) recommends RRBSO once childbearing is complete and patients are age 40 for BRCA1(B1) patients and 45 years for BRCA2 (B2) carriers, in keeping with international guidelines. Historically, worldwide uptake of RRBSO has been highly variable, potentially leading to unnecessary OC cases.
Methods
This is a retrospective study, carried out at the RM. All BRCA1/2 carriers at RM are recorded and followed using the RM Cancer Genetics BRCA carrier register. The electronic patient record was used to obtain the following information: BRCA gene, age of RRBSO, findings at RRBSO and OC history. The primary endpoint was to determine the uptake of RRBSO in age-appropriate carriers. Secondary endpoints include rates of occult malignancy at RRBSO, and rates of peritoneal malignancy in carriers who had previously undergone RRBSO.
Results
1450 female gene mutation carriers were identified, of which 1129 met our age criteria (594 B1 and 535 B2). Of these 1129 BRCA carriers, 140 B1 and 100 B2 carriers were excluded as they were diagnosed with OC before BRCA testing. 16 carriers (10B1 and 6B2) were excluded as they had BSO for other reasons. 444 B1 and 429 B2 met all exclusion criteria. RRBSO was undertaken in 339 (76.3%) B1 carriers and 342 (79.7%) B2 patients. A further 16Y B1 and 14B2 have been referred and are awaiting surgery. Occult high grade serous OC was found in 9 B1 and 3 B2 carriers. B1 carriers also had serous intra-epithelial carcinoma (4 patients), and 2 had unrelated pathology. In B2 carriers, 1 had a grade 2 endometrioid adenocarcinoma of the FT, 2 had metastatic lobular breast cancer and 1 had unrelated pathology. Primary peritoneal cancer was diagnosed in 3 B1 and 2 B2 carriers despite prior RRBSO.
Conclusions
There is a high uptake of RRBSO amongst BRCA1 and BRCA2 carriers at RM, and low rates of occult malignancy and primary peritoneal cancer. Further work is being undertaken to look at other factors for RRBSO uptake, and risks of OC below recommended ages for BRCA carriers.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.