title: Impact of full field digital mammography on the classification and mammographic characteristics of interval breast cancers.
abstract: OBJECTIVE
  Full field digital mammography (FFDM) is increasingly replacing screen film mammography (SFM) in breast screening programs. Interval breast cancers are an issue in all screening programs and the purpose of our study is to assess the impact of FFDM on the classification of interval breast cancers at independent blind review and to compare the mammographic features of interval cancers at FFDM and SFM.
  
  
  METHODS
  This study included 138 cases of interval breast cancer, 76 following an FFDM screening examination and 62 following screening with SFM. The prior screening mammogram was assessed by each of five consultant breast radiologists who were blinded to the site of subsequent cancer. Subsequent review of the diagnostic mammogram was performed and cases were classified as missed, minimal signs, occult or true interval. Mammographic features of the interval cancer at diagnosis and any abnormality identified on the prior screening mammogram were recorded.
  
  
  RESULTS
  The percentages of cancers classified as missed at FFDM and SFM did not differ significantly, 10.5% (8 of 76) at FFDM and 8.1% (5 of 62) at SFM (p=.77). There were significantly less interval cancers presenting as microcalcifications (alone or in association with another abnormality) following screening with FFDM, 16% (12 of 76) than following a SFM examination, 32% (20 of 62) (p=.02).
  
  
  CONCLUSIONS
  Interval breast cancers continue to pose a problem at FFDM. The switch to FFDM has changed the mammographic presentation of interval breast cancer, with less interval cancers presenting in association with microcalcifications.
authors: BreastCheck (The Irish National Breast Screening Program) and the Mater Misericordiae University Hospital, Eccles St, Dublin 7, Ireland. Electronic address: marktknox@gmail.com.
authors: Mark
authors: M
authors: Knox
authors: BreastCheck (The Irish National Breast Screening Program) and the Mater Misericordiae University Hospital, Eccles St, Dublin 7, Ireland. Electronic address: angelaobrien@doctors.org.uk.
authors: Angela
authors: A
authors: O'Brien
authors: BreastCheck (The Irish National Breast Screening Program) and the Mater Misericordiae University Hospital, Eccles St, Dublin 7, Ireland. Electronic address: endrebacsi@freemail.hu.
authors: Endre
authors: E
authors: Szabó
authors: BreastCheck (The Irish National Breast Screening Program) and the Mater Misericordiae University Hospital, Eccles St, Dublin 7, Ireland. Electronic address: csmith@mater.ie.
authors: Clare S
authors: CS
authors: Smith
authors: BreastCheck (The Irish National Breast Screening Program) and the Mater Misericordiae University Hospital, Eccles St, Dublin 7, Ireland. Electronic address: helen.fenlon@cancerscreening.ie.
authors: Helen M
authors: HM
authors: Fenlon
authors: BreastCheck (The Irish National Breast Screening Program) and the Mater Misericordiae University Hospital, Eccles St, Dublin 7, Ireland. Electronic address: michelle.mcnicholas@cancerscreening.ie.
authors: Michelle M
authors: MM
authors: McNicholas
authors: BreastCheck (The Irish National Breast Screening Program) and the Mater Misericordiae University Hospital, Eccles St, Dublin 7, Ireland. Electronic address: fidelma.flanagan@cancerscreening.ie.
authors: Fidelma L
authors: FL
authors: Flanagan
mesh_terms: D000368:Aged; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D002114:Calcinosis / Q000000981:diagnostic imaging; D055088:Early Detection of Cancer / Q000379:methods; D005260:Female; D006801:Humans; D008327:Mammography; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D011856:Radiographic Image Enhancement
keywords: Breast screening; Full field digital mammography; Interval breast cancer; Screen film mammography