Association between risk-reducing salpingooophorectomy and bone health in women with hereditary breast and ovarian cancer syndrome.

To explore any association between risk-reducing bilateral salpingooophorectomy (RRSO) and bone mineral density (BMD) and fracture risk among women with a germline likely pathogenic or pathogenic variant in genes causing hereditary breast and ovarian cancer. Longitudinal prospective observational study. Clinical, biochemical, and BMD assessments were performed at study entry (V0) and after 18 months (V1). Four groups were compared: RRSO (RRSO in premenopause without hormone therapy [HT]), RRSO+HT (RRSO followed by HT), MEN (natural menopause with/without RRSO), and FERT (regular menstrual cycles not undergoing RRSO). One hundred four women were enrolled (52 BRCA1 germline likely pathogenic or pathogenic variant, 49 BRCA2, 3 other genes): 30 RRSO, 10 RRSO+HT, 29 MEN, 35 FERT. The V0 evaluation was performed at 2.85 ± 2.03 years from RRSO. At V0, no difference in lumbar spine (LS) and femoral neck BMD was detected comparing RRSO to RRSO+HT, MEN, and FERT. At V1 RRSO was associated with higher femoral neck BMD than MEN (P = 0.016), together with worse LS BMD than FERT (P = 0.045). The temporal decline of LS BMD in RRSO was more pronounced than MEN (P = 0.019). Calculated risk of fracture (Fracture Risk Assessment Tool [FRAX]) at V0 was lower in RRSO than MEN (P < 0.001), similar to RRSO+HT and FERT; at V1, FRAX was higher in RRSO than FERT (P = 0.014). RRSO was associated with greater and prolonged bone health decline in women ovariectomized at premenopausal age, not receiving HT. This high-risk population deserves long-term BMD monitoring, and HT mitigating effect might be considered.