title: Mammography screening and risk of breast cancer death: a population-based case-control study.
abstract: BACKGROUND
  Because the efficacy of mammography screening had been shown in randomized controlled trials, the focus has turned on its effectiveness within the daily practice. Using individual data of women invited to screening, we conducted a case-control study to assess the effectiveness of the Dutch population-based program of mammography screening.
  
  
  METHODS
  Cases were women who died from breast cancer between 1995 and 2003 and were closely matched to five controls on year of birth, year of first invitation, and number of invitations before case's diagnosis. ORs and 95% confidence intervals (CI) for the association between attending either of three screening examinations prior to diagnosis and the risk of breast cancer death were calculated using conditional logistic regression and corrected for self-selection bias.
  
  
  RESULTS
  We included 755 cases and 3,739 matched controls. Among the cases, 29.8% was screen-detected, 34.3% interval-detected, and 35.9% never-screened. About 29.5% of the never-screened cases had stage IV tumor compared with 5.3% of the screen-detected and 15.1% of the interval-detected cases. The OR (95% CIs), all ages (49-75 years), was 0.51 (0.40-0.66) and for the age groups 50-69, 50-75, and 70-75 years were 0.61 (0.47-0.79), 0.52 (CI 0.41-0.67), and 0.16 (0.09-0.29), respectively.
  
  
  CONCLUSIONS
  The study provides evidence for a beneficial effect of early detection by mammography screening in reducing the risk of breast cancer death among women invited to and who attended the screening.
  
  
  CONCLUSIONS
  This is the first case-control study that accurately accounts for equal screening opportunity for both cases and matched controls by number of invitations before case's diagnosis.
authors.affiliation: Department of Public Health, Erasmus MC, University Medical Center Rotterdam, P.O. Box 2040, Rotterdam 3000 CA, The Netherlands. s.otto@erasmusmc.nl
authors.forename: Suzie J
authors.initials: SJ
authors.lastname: Otto
authors.forename: Jacques
authors.initials: J
authors.lastname: Fracheboud
authors.forename: André L M
authors.initials: AL
authors.lastname: Verbeek
authors.forename: Rob
authors.initials: R
authors.lastname: Boer
authors.forename: Jacqueline C I Y
authors.initials: JC
authors.lastname: Reijerink-Verheij
authors.forename: Johannes D M
authors.initials: JD
authors.lastname: Otten
authors.forename: Mireille J M
authors.initials: MJ
authors.lastname: Broeders
authors.forename: Harry J
authors.initials: HJ
authors.lastname: de Koning
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000401:mortality*; D016022:Case-Control Studies; D055088:Early Detection of Cancer / Q000379:methods; D005260:Female; D006801:Humans; D008327:Mammography / Q000379:methods*; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology