title: Breast screening using 2D-mammography or integrating digital breast tomosynthesis (3D-mammography) for single-reading or double-reading--evidence to guide future screening strategies.
abstract: OBJECTIVE
  We compared detection measures for breast screening strategies comprising single-reading or double-reading using standard 2D-mammography or 2D/3D-mammography, based on the 'screening with tomosynthesis or standard mammography' (STORM) trial.
  
  
  METHODS
  STORM prospectively examined screen-reading in two sequential phases, 2D-mammography alone and integrated 2D/3D-mammography, in asymptomatic women participating in Trento and Verona (Northern Italy) population-based screening services. Outcomes were ascertained from assessment and/or excision histology or follow-up. For each screen-reading strategy we calculated the number of detected and non-detected (including interval) cancers, cancer detection rates (CDRs), false positive recall (FPR) measures and incremental CDR relative to a comparator strategy. We estimated the false:true positive (FP:TP) ratio and sensitivity of each mammography screening strategy. Paired binary data were compared using McNemar's test.
  
  
  RESULTS
  Amongst 7292 screening participants, there were 65 (including six interval) breast cancers; estimated first-year interval cancer rate was 0.82/1000 screens (95% confidence interval (CI): 0.30-1.79/1000). For single-reading, 35 cancers were detected at both 2D and 2D/3D-mammography, 20 cancers were detected only with 2D/3D-mammography compared with none at 2D-mammography alone (p<0.001) and 10 cancers were not detected. For double-reading, 39 cancers were detected at 2D-mammography and 2D/3D-mammography, 20 were detected only with 2D/3D-mammography compared with none detected at 2D-mammography alone (p<0.001) and six cancers were not detected. The incremental CDR attributable to 2D/3D-mammography (versus 2D-mammography) of 2.7/1000 screens (95% CI: 1.6-4.2) was evident for single and for double-reading. Incremental CDR attributable to double-reading (versus single-reading) of 0.55/1000 screens (95% CI: -0.02-1.4) was evident for 2D-mammography and for 2D/3D-mammography. Estimated FP:TP ratios showed that 2D/3D-mammography screening strategies had more favourable FP to TP trade-off and higher sensitivity, applying single-reading or double-reading, relative to 2D-mammography screening.
  
  
  CONCLUSIONS
  The evidence we report warrants rethinking of breast screening strategies and should be used to inform future evaluations of 2D/3D-mammography that assess whether or not the estimated incremental detection translates into improved screening outcomes such as a reduction in interval cancer rates.
authors.affiliation: Screening and Test Evaluation Program (STEP), School of Public Health, Sydney Medical School, University of Sydney, Sydney, Australia. Electronic address: nehmath@med.usyd.edu.au.
authors.forename: Nehmat
authors.initials: N
authors.lastname: Houssami
authors.affiliation: Screening and Test Evaluation Program (STEP), School of Public Health, Sydney Medical School, University of Sydney, Sydney, Australia.
authors.forename: Petra
authors.initials: P
authors.lastname: Macaskill
authors.affiliation: U.O. Senologia Clinica e Screening Mammografico, Department of Diagnostics, Azienda Provinciale Servizi Sanitari (APSS), Trento, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Bernardi
authors.affiliation: Centro di Prevenzione Senologica, Marzana, Verona, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Caumo
authors.affiliation: U.O. Senologia Clinica e Screening Mammografico, Department of Diagnostics, Azienda Provinciale Servizi Sanitari (APSS), Trento, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Pellegrini
authors.affiliation: Centro di Prevenzione Senologica, Marzana, Verona, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Brunelli
authors.affiliation: U.O. Senologia Clinica e Screening Mammografico, Department of Diagnostics, Azienda Provinciale Servizi Sanitari (APSS), Trento, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Tuttobene
authors.affiliation: Centro di Prevenzione Senologica, Marzana, Verona, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Bricolo
authors.affiliation: U.O. Senologia Clinica e Screening Mammografico, Department of Diagnostics, Azienda Provinciale Servizi Sanitari (APSS), Trento, Italy.
authors.forename: Carmine
authors.initials: C
authors.lastname: Fantò
authors.affiliation: U.O. Senologia Clinica e Screening Mammografico, Department of Diagnostics, Azienda Provinciale Servizi Sanitari (APSS), Trento, Italy.
authors.forename: Marvi
authors.initials: M
authors.lastname: Valentini
authors.affiliation: U.O. Senologia Clinica e Screening Mammografico, Department of Diagnostics, Azienda Provinciale Servizi Sanitari (APSS), Trento, Italy; Centro di Prevenzione Senologica, Marzana, Verona, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Ciatto
mesh_terms: D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000473:pathology; D019317:Evidence-Based Medicine; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007558:Italy / Q000453:epidemiology; D008327:Mammography / Q000379:methods*; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D011857:Radiographic Image Interpretation, Computer-Assisted; D015203:Reproducibility of Results; D013997:Time Factors
keywords: Breast cancer; Digital breast tomosynthesis; Interval cancer; Mammography; Population screening; Screen-reading