Article Text
Abstract
Introduction/Background BRCA1 and BRCA2 carriers face difficult choices/decisions regarding surgical prevention for breast and ovarian cancer. Clinician counselling must accurately reflect available evidence, which for breast cancer risk following risk reducing salpingo-oophorectomy (RRSO) is now conflicting.
Methodology We searched seven databases (till June 2022) for studies reporting primary breast cancer (PBC), contralateral breast cancer (CBC) risk and breast cancer specific mortality (BCSM) post-RRSO in BRCA1 and BRCA2 carriers without a personal history of ovarian cancer. Baseline meta-analysis quantified PBC risk/CBC risk/BCSM amongst BRCA1 and BRCA2 carriers. Subgroup analyses by mutation and menopause status were undertaken. Numbers needed to treat (NNT) for statistically significant outcomes were calculated.
Results Baseline analysis revealed RRSO does not significantly reduce PBC-risk (RR=0.84, 95%CI:0.59–1.21), nor CBC-risk (RR=0.95, 95%CI:0.65–1.39) in BRCA1 and BRCA2 carriers combined but reduces BCSM in BC-affected BRCA1 and BRCA2 carriers combined (RR=0.26, 95%CI:0.18–0.39). Subgroup analyses showed RRSO does not significantly reduce PBC-risk (RR=0.89, 95%CI:0.68–1.17) or CBC-risk (RR=0.85, 95%CI:0.59–1.24) in BRCA1-carriers alone; nor reduce CBC-risk in BRCA2-carriers alone (RR=0.35, 95%CI:0.07–1.74). PBC-risk in pre-menopausal (RR=0.84, 95%CI:0.62–1.12) or post-menopausal BRCA1 and BRCA2 carriers combined (RR=0.65, 95%CI:0.18–2.42) was not significantly reduced. RRSO significantly reduced PBC-risk in BRCA2-carriers alone (RR=0.63, 95%CI:0.41–0.97); and BCSM in BC-affected BRCA1-carriers alone (RR=0.46, 95%CI:0.30–0.70). NNT=17.9 RRSOs to prevent one PBC-case in BRCA2-carriers alone. While, 5.4 and 17.8 RRSOs are needed to prevent one BC-death in BC-affected BRCA1 and BRCA2-carriers combined and BRCA1-carriers alone respectively.
Conclusion Whilst RRSO does not reduce PBC-risk or CBC-risk in BRCA1 and BRCA2 carriers combined, it does appear to improve BC-survival in BC-affected BRCA1 and BRCA2 carriers combined and may prevent PBC in BRCA2 carriers alone.