title: Interval breast cancers in screening: the effect of mammography review method on classification.
abstract: Surveillance of interval cancers (IC) lacks standardisation of review methodologies. We investigated the extent to which 'informed' or 'blinded' review may affect IC classification. This is a retrospective study of 100 validated screening mammograms (20 IC, 80 negative screens) independently reviewed by six radiologists. Three sequenced review methods with increasing information were used: (1) blinded (no IC information, case mix), (2) partially informed, and (3) fully informed. IC 'screening error' (SE) reports averaged 24% (10-40), 33% (20-55), and 42% (35-50) for phases 1, 2, and 3, while 'minimal signs' (MS) reports averaged 6% (5-15), 10% (10-20), and 20% (15-30), respectively. Negative mammograms classification was MS in 18% (7-39) or SE in 19% (11-29), respectively. MS or SE classification was more likely for method 2 (OR=1.78, p=0.033) and method 3 (OR=3.91, p=0.000) relative to method 1, but no reader effect was evident. Inter-observer agreement in classifying at method 1 was slight (k 0.20), lowest (k 0.06) for MS, and fair (k 0.25) for negative and SE categories. More 'informed' review is more likely to yield an IC classification as MS or SE. Due to expected variability, review methods need standardisation to improve screening quality. Our data support blinded review of IC in mammography screening.
authors.affiliation: Centro per lo Studio e la Prevenzione Oncologica,Viale A. Volta 171, 5131, Florence, Italy. s.ciatto@cspo.it
authors.forename: Stefano
authors.initials: S
authors.lastname: Ciatto
authors.forename: Sandra
authors.initials: S
authors.lastname: Catarzi
authors.forename: Maria Perla
authors.initials: MP
authors.lastname: Lamberini
authors.forename: Gabriella
authors.initials: G
authors.lastname: Risso
authors.forename: Gianni
authors.initials: G
authors.lastname: Saguatti
authors.forename: Teresa
authors.initials: T
authors.lastname: Abbattista
authors.forename: Francesca
authors.initials: F
authors.lastname: Martinelli
authors.forename: Nehmat
authors.initials: N
authors.lastname: Houssami
mesh_terms: D001943:Breast Neoplasms / Q000145:classification* / Q000000981:diagnostic imaging*; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008327:Mammography; D008403:Mass Screening / Q000592:standards*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity