title: Delayed diagnosis of breast cancer in women recalled for suspicious screening mammography.
abstract: OBJECTIVE
  To determine the frequency, pathology and causes of a delay in cancer diagnosis in women recalled for suspicious screening mammography.
  
  
  METHODS
  We included all 290,943 screening mammograms of women aged 50-75 years, who underwent biennial screening mammography between 1st January 1995 and 1st January 2006. During a follow-up period of at least 2 years, clinical data, breast imaging reports, biopsy results and breast surgery reports were collected of all 3513 women with a positive screening result. Tumour stages of breast cancers with a diagnostic delay (defined as breast cancer confirmation more than 3 months following a positive mammography screen) were compared with those of cancers diagnosed within 3 months following referral and with interval cancers.
  
  
  RESULTS
  A diagnostic delay occurred in 97 (6.5%) of 1503 screen-detected cancers. These 97 false-negative assessments comprised significantly more ductal cancers in situ (26.8%) than did cancers with an adequate assessment after recall (15.5%, p=0.004) or interval cancers (3.7%, p<0.001). Compared with interval cancers, cancers with a false-negative assessment had a more favourable tumour size (T1a-c, 87.3% versus T1a-c, 46.4%; p<0.001) and showed significantly fewer cases with axillary lymph node metastases (22.5% versus 48.2%; p<0.001). Between hospitals having performed the workup of at least 500 referred women each, the percentage of women with a false-negative assessment varied from 5.0% to 9.1% (p=0.03). In these hospitals, improper classification of lesions at diagnostic mammography comprised 64.4% of false-negative assessments.
  
  
  CONCLUSIONS
  We found that 6.5% of recalled women experienced a delay in breast cancer diagnosis, with significant performance variations between hospitals.
authors.affiliation: Department of Radiology, Catharina Hospital, Eindhoven, The Netherlands. LEMDuijm@hotmail.com
authors.forename: Lucien E M
authors.initials: LE
authors.lastname: Duijm
authors.forename: Johanna H
authors.initials: JH
authors.lastname: Groenewoud
authors.forename: Harry J
authors.initials: HJ
authors.lastname: de Koning
authors.forename: Jan Willem
authors.initials: JW
authors.lastname: Coebergh
authors.forename: Mike
authors.initials: M
authors.lastname: van Beek
authors.forename: Marianne J H H
authors.initials: MJ
authors.lastname: Hooijen
authors.forename: Lonneke V
authors.initials: LV
authors.lastname: van de Poll-Franse
mesh_terms: D000368:Aged; D001706:Biopsy; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000473:pathology; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008134:Long-Term Care / Q000379:methods; D008207:Lymphatic Metastasis; D008327:Mammography / Q000379:methods / Q000592:standards; D008403:Mass Screening / Q000379:methods* / Q000592:standards; D008875:Middle Aged; D009367:Neoplasm Staging; D009426:Netherlands / Q000453:epidemiology; D011379:Prognosis; D011446:Prospective Studies; D012017:Referral and Consultation / Q000706:statistics & numerical data; D013997:Time Factors