Breast screening with ultrasound in women with mammography-negative dense breasts: Evidence on incremental cancer detection and false positives, and associated cost

BackgroundWe evaluated the contribution of ultrasound (US) in detecting breast cancer in women with dense breasts and negative mammograms.Methods9157 (35.8%) of 25,572 self-referring women during 2000–2007 had BI-RADS D3–4 negative mammograms – all were screened with bilateral US.ResultsUS detected 37 cancers – incremental cancer detection rate (ICDR) was 0.40% (95% CI: 0.39–0.41%); ICDR was 0.33% in women <50 and 0.51% in those 50 years and older. US detected a larger proportion of cancers below age 50 compared to older women. US-only detected cancers had a more favourable stage (pTis–pT1a–pT1b: 64.8% versus 35.5%, p = 0.001; pN1: 13.5% versus 31.3%, p = 0.047) than cancers detected on mammography. US caused additional investigations in 4.9% of women and benign surgical biopsies in 0.9%. Cost per US-screened woman, and per US-detected cancer ranged between €59–62 and €14,618–15,234, respectively.ConclusionUS detects early-stage cancers in women with mammography-negative dense breasts, with higher contribution in women younger than 50 years.