title: An investigation into why two-view mammography is better than one-view in breast cancer screening.
abstract: OBJECTIVE
  To determine why two-view mammography in screening for breast cancer is more effective than using a single medio-lateral oblique view.
  
  
  METHODS
  In the United Kingdom Coordinating Committee on Cancer Research randomized trial of one- vs two-view mammography in breast cancer screening the oblique view was assessed by one radiologist and two views (oblique and cranio-caudal) assessed by another. For the present study the mammographic films were retrieved from the screening centres and assessed by three consultant radiologists. Mammographic films were available from 110 women; 87 had their breast cancer detected by both one and two views and in 23 it was missed by one view but detected using two views. Outcome measures were breast size, location and size of the cancer, mammographic features, presence of microcalcification and overall radiological assessment.
  
  
  RESULTS
  Although 23 cancers were missed in the original trial when one view was used, only two were not visible on the oblique view. Cancers missed using a single oblique view (and only detected if the cranio-caudal view was available with the oblique) tended to be smaller by about 4 mm (P = 0.05), centrally located in the breast (P = 0.16), not spiculated or round, (P </= 0. 001) and lacked microcalcification (P = 0.15). Breast size and breast radiographic density were not significantly associated with breast cancer detection.
  
  
  CONCLUSIONS
  The results provide the basis for the observation that two-view mammographic screening is more effective than one-view mammographic screening.Hackshaw, A. (2000). Clinical Radiology55, 454-458.
authors.affiliation: CRC Cancer Screening Group, Department of Environmental and Preventive Medicine, Wolfson Institute of Preventive Medicine, St Bartholomew's and the Royal London School of Medicine and Dentistry, Charterhouse Square, London, EC1M 6BQ.
authors.forename: A K
authors.initials: AK
authors.lastname: Hackshaw
authors.forename: N J
authors.initials: NJ
authors.lastname: Wald
authors.forename: M J
authors.initials: MJ
authors.lastname: Michell
authors.forename: S
authors.initials: S
authors.lastname: Field
authors.forename: A R
authors.initials: AR
authors.lastname: Wilson
mesh_terms: D001943:Breast Neoplasms / Q000150:complications / Q000175:diagnosis*; D002114:Calcinosis / Q000175:diagnosis / Q000209:etiology; D005260:Female; D006801:Humans; D008327:Mammography / Q000379:methods*; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D012680:Sensitivity and Specificity