RESUMEN
This article evaluates the breast cancer (BC) screening efficacy of biannual ultrasound (US) in three different risk categories. In a single-center, prospective, nonrandomized comparison study, BRCA mutation carriers and women with high risk (HR) or intermediate risk (IR) received mammography (MMG), ultrasound, (US) and Magnetic Resonance Imaging (MRI), scheduled according to the risk categories. Single and combined sensitivity were evaluated in specific groups of risk and the US performance at six-monthly interval was notably considered. Among 2,313 asymptomatic women at different risk (136 mutation carriers, 1,749 at HR and 428 at IR) 211 developed a BC, of which 193 (91.5%) were screen detected BC (SDBC) and 18 (8.5%) were interval BC (IBC). The SDBC detection rate (DR) was 11.2 per 1.000 person-years (37.9, 8.5 and 16.1 for BRCA, HR and IR, respectively); 116 BC were detected by MMG (DR = 6.6 × 1,000 persons-years), 62 by US (DR = 3.6 × 1,000 persons-years) and 15 by MRI, that was applied only in 60 BRCA women (DR = 37 × 1,000 persons-years). At the six-monthly US, 52 BC were detected (DR = 3.0 × 1,000 persons/years), of which 8 were BRCA-related. The most sensitive technique was MRI (93.7%) followed by MMG (55%) and US (29.4%). Combined sensitivity for MMG plus US was 100% in HR and 80.4% for IR women (p < 0.01). In BRCA mutated patients, MRI alone with annual US performed after six months, could be offered. In HR patients, MMG plus biannual US provide the most sensitive diagnosis and for IR group an annual MMG could be sufficient.