title: Evidence of the effect of adjunct ultrasound screening in women with mammography-negative dense breasts: interval breast cancers at 1 year follow-up.
abstract: Surveillance of interval cancers (IC) provides a measure of breast screening efficacy. Increased breast density is a predictor of breast cancer risk and of the risk of IC in screening. Improving screening sensitivity in women with dense breasts, through adjunct ultrasound (US), may potentially reduce IC; however this has not been proven. We report on first-year IC in a retrospective cohort of 8865 women who had 19,728 screening examinations (2001-2006): women with non-dense (D1-D2) breasts received mammography (M) screening, and women with dense (D3-D4) breasts also received ultrasound. Data linkage with both hospital discharge records and cancer registry databases was used to identify IC. Underlying cancer rates (cancers observed within 1-year from screening) were 6.3/1000 screens in the D1-D2 group and 8.3/1000 screens in the D3-D4 group. Cancer detection rate (CDR) was 5.98/1000 in all screening examinations; in D3-D4 breasts ultrasound had an additional CDR of 4.4/1000 screens. There were 21 first-year IC, an overall interval cancer rate (ICR) of 1.07/1000 negative screens: 0.95/1000 in women < 50 years and 1.16/1000 screens in women ≥ 50 years. ICR by breast density were 1.0/1000 negative screens in D1-D2, and 1.1/1000 negative screens in D3-D4. Interval cancers were early stage (in situ or small invasive) cancers, almost all were node-negative. Screening sensitivity was 83.5% for mammography alone in D1-D2 breasts relative to 86.7% for mammography with ultrasound in D3-D4 breasts. Our study shows that including ultrasound as adjunct screening in women with D3-D4 breasts brings the IC rate to similar levels as IC in non-dense breasts--this suggests that additional cancer detection by ultrasound is likely to improve screening benefit in dense breasts, and supports the implementation of a randomised trial of adjunct ultrasound in women with increased breast tissue density.
authors.affiliation: Ambulatori Raphael, Calcinato (BS), Italy. v.corsetti@raphael.coop
authors.forename: Vittorio
authors.initials: V
authors.lastname: Corsetti
authors.forename: Nehmat
authors.initials: N
authors.lastname: Houssami
authors.forename: Marco
authors.initials: M
authors.lastname: Ghirardi
authors.forename: Aurora
authors.initials: A
authors.lastname: Ferrari
authors.forename: Michela
authors.initials: M
authors.lastname: Speziani
authors.forename: Sergio
authors.initials: S
authors.lastname: Bellarosa
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Remida
authors.forename: Cristina
authors.initials: C
authors.lastname: Gasparotti
authors.forename: Enzo
authors.initials: E
authors.lastname: Galligioni
authors.forename: Stefano
authors.initials: S
authors.lastname: Ciatto
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008327:Mammography / Q000379:methods*; D008403:Mass Screening / Q000379:methods; D008495:Medical Oncology / Q000379:methods; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging / Q000379:methods; D011871:Radiology / Q000379:methods; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000379:methods*; D016217:Ultrasonography, Mammary