Breast density changes after risk-reducing salpingo-oophorectomy in women with a pathogenic germline variant in BRCA1 or BRCA2
Menée à partir de données de 5 études du consortium international "IBCCS" portant sur 691 femmes ayant réalisé au moins deux mammographies de dépistage et présentant une mutation BRCA, cette étude analyse l'effet d'une salpingo-ovariectomie prophylactique sur la densité mammaire
Background: We studied change in mammographic density (MD) among premenopausal women with a pathogenic germline variant (PGV) in BRCA1 or BRCA2 genes, comparing those who did and did not undergo risk-reducing salpingo-oophorectomy (RRSO) in the interval between mammograms, accounting for changes in exogenous oral contraceptive (OC) or hormone replacement therapy (HRT) use.
Methods: From five studies of the international IBCCS consortium, we included 691 participants who had two or more screening mammograms available, were less than 47 years at time of RRSO (N=208) or premenopausal at all mammograms without RRSO (N=483). MD metrics [Percent density (PD), dense area (DA), and non-dense area (NDA)] were quantified using STRATUS. Multivariable linear mixed models assessed changes in MD metrics between groups, adjusting for confounders.
Results: Mean PD at first mammogram was 26.8% ± 15.3 (RRSO) and 31.3% ± 18.1 (no RRSO). In a median 1.1 years between mammograms, PD decreased on average 0.9% (95% CI: -1.6; -0.2) among women who did not undergo RRSO in the interval between mammograms compared to 5.9% (95% CI: -7.4; -4.5) among women who underwent RRSO in the interval (adjusted difference: -5.9%, 95%CI: -9.5; -2.2, p=0.002). Results were driven primarily by MD changes among BRCA2 PGV carriers. Use of HRT after RRSO attenuated the decline in PD.
Conclusions: On average, PD and DA decrease following RRSO in premenopausal carriers, particularly among BRCA2 PGV carriers. HRT formulation affects MD changes.
Impact: Decrease in mammographic density may inform the potential protective effect of RRSO against breast cancer.
Cancer Epidemiology, Biomarkers & Prevention , article en libre accès, 2025