Progestin-only implant and breast cancer risk in adolescents and premenopausal women: A systematic review and meta-analysis
A partir d'une revue systématique de la littérature publiée jusqu'en avril 2026 (5 études), cette méta-analyse évalue l'association entre une contraception réversible de longue durée par implant sous-cutané progestatif et le risque de cancer du sein chez les adolescentes et les femmes préménopausées sans antécédent de la maladie
Long-acting reversible contraception with progestin-only subdermal implants is widely adopted. However, the breast cancer (BC) risk signal attributable to implants remains under-characterized, limiting evidence-based counseling. We systematically searched PubMed/MEDLINE, Embase, and Scopus,and screened references for observational cohort and case-control studies evaluating progestin-only implant versus non-use hormonal contraception in adolescents and premenopausal women without prior BC. The primary endpoint was incident BC (invasive with/without in situ, per study definition). Maximally adjusted effect estimates were extracted; measures were harmonized to odds ratios (ORs). Risk of bias was assessed with ROBINS-E. Pooled estimates used inverse-variance random-effects meta-analysis; heterogeneity was quantified with I² and Tau². Five studies met inclusion criteria (3 nationwide cohorts from Denmark/Sweden and 2 nested case-control studies from the UK and Australia). Across cohort studies, implant exposure accounted for 1659,309 person-years with 510 BC events. The largest case-control dataset included 67,470 BC cases. Study-specific adjusted estimates were: Morch 2017 RR 0.93 (95% CI 0.48–1.80), Fitzpatrick 2023 OR 1.22 (0.93–1.60), Hadizadeh 2025 HR 1.22 (1.11–1.35), Hultstrand 2022 IRR 1.22 (0.98–1.52), and Tuesley 2025 OR 1.24 (1.17–1.32). The pooled effect showed higher incident BC risk with implant exposure (OR 1.23, 95% CI 1.19–1.27, p < 0.0001) with no observed heterogeneity (I²=0%; Tau²=0). In contemporary population-based data, progestin-only subdermal implant use is associated with a modest but statistically increase (∼23%) in incident BC risk versus non-use. Given low baseline incidence in younger women, absolute risk impact is likely small, but the signal is decision-relevant for shared contraceptive counseling, particularly in patients with elevated baseline BC risk.
Cancer Epidemiology , article en libre accès, 2026