title: Effectiveness of organised versus opportunistic mammography screening.
abstract: BACKGROUND
  Detailed comparison of effectiveness between organised and opportunistic mammography screening operating in the same country has seldom been carried out.
  
  
  METHODS
  Prognostic indicators, as defined in the European Guidelines, were used to evaluate screening effectiveness in Switzerland. Matching of screening programmes' records with population-based cancer registries enabled to compare indicators of effectiveness by screening and detection modality (organised versus opportunistic screening, unscreened, interval cancers). Comparisons of prognostic profile were also drawn with two Swiss regions uncovered by service screening of low and high prevalence of opportunistic screening, respectively.
  
  
  RESULTS
  Opportunistic and organised screening yielded overall little difference in prognostic profile. Both screening types led to substantial stage shifting. Breast cancer prognostic indicators were systematically more favourable in Swiss regions covered by a programme. In regions without a screening programme, the higher the prevalence of opportunistic screening, the better was the prognostic profile.
  
  
  CONCLUSIONS
  Organised screening appeared as effective as opportunistic screening. Mammography screening has strongly influenced the stage distribution of breast cancer in Switzerland, and a favourable impact on mortality is anticipated. Extension of organised mammography screening to the whole of Switzerland can be expected to further improve breast cancer prognosis in a cost-effective way.
authors.affiliation: Cancer Epidemiology Unit, University Institute of Social and Preventive Medicine (IUMSP), Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland. Jean-Luc.Bulliard@chuv.ch
authors.forename: J-L
authors.initials: JL
authors.lastname: Bulliard
authors.forename: C
authors.initials: C
authors.lastname: Ducros
authors.forename: C
authors.initials: C
authors.lastname: Jemelin
authors.forename: B
authors.initials: B
authors.lastname: Arzel
authors.forename: G
authors.initials: G
authors.lastname: Fioretta
authors.forename: F
authors.initials: F
authors.lastname: Levi
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D008327:Mammography / Q000706:statistics & numerical data*; D008403:Mass Screening / Q000706:statistics & numerical data*; D008875:Middle Aged; D009367:Neoplasm Staging; D010342:Patient Acceptance of Health Care; D011159:Population Surveillance; D015995:Prevalence; D011379:Prognosis; D015397:Program Evaluation; D019984:Quality Indicators, Health Care; D013557:Switzerland