title: [Evaluating colorectal cancer screening strategies (immunological test vs biochemical test) in Catalonia, Spain 2008-2010].
abstract: BACKGROUND
  The aim of this study was to evaluate the screening strategy (quantitative immunological test vs biochemical test) in a population-based screening program for colorectal cancer (CRC) in Catalonia.
  
  
  METHODS
  The fourth round of a screening program for CRC with a fecal occult blood test was implemented in Hospitalet de Llobregat during 2008-2010. A biochemical test was offered to 50,227 individuals and a quantitative immunological test was offered to 12,707 individuals. We analysed differences according to the screening strategy in the following variables: acceptability of the target population (participation, dropouts, and adherence to colonoscopy), diagnostic accuracy (positive predictive value and detection rates), results (size and location of lesions, staging of CRC) and resources (number of colonoscopies needed and time interval between the positive test and colonoscopy).
  
  
  RESULTS
  Participation was higher among individuals who used the immunological test (OR: 1.35; CI95%:1.27-1.42). Detection rates for adenomas and cancer were also higher for the immunological test, hightlighting the detection rate for high-risk adenomas (26.7‰ vs. 3.0‰). The positive predictive value for high-risk adenomas was 45.0% and 46.9% in the immunological test and guaiac test, respectively. The number of colonoscopies needed to detect cancer with the immunological test was almost two-fold than those needed with the guaiac test (13.6 vs 7.4).
  
  
  CONCLUSIONS
  The immunological test is a good screening strategy particularly sensitive for detecting high-risk adenomas. However, it is paramount to have enough resources to assure the quality of the CRC screening due to the large number of colonoscopies that would be required.
authors.affiliation: Grupo de Prevención y Control del Cáncer, Instituto de Investigación Biomédica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, España. mgarcia@iconcologia.net
authors.forename: Montse
authors.initials: M
authors.lastname: García Martínez
authors.forename: Gemma
authors.initials: G
authors.lastname: Binefa Rodríguez
authors.forename: Núria
authors.initials: N
authors.lastname: Milà Díaz
authors.forename: Francisco
authors.initials: F
authors.lastname: Rodríguez Moranta
authors.forename: Núria
authors.initials: N
authors.lastname: Gonzalo Diego
authors.forename: Carmen
authors.initials: C
authors.lastname: Muñoz Sánchez
authors.forename: Josep Alfons
authors.initials: JA
authors.lastname: Espinàs Piñol
authors.forename: Josep Maria
authors.initials: JM
authors.lastname: Borràs Andrés
authors.forename: Víctor
authors.initials: V
authors.lastname: Moreno Aguado
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000517:prevention & control; D000368:Aged; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000517:prevention & control; D055088:Early Detection of Cancer / Q000379:methods*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009780:Occult Blood; D010342:Patient Acceptance of Health Care; D011237:Predictive Value of Tests; D055502:Secondary Prevention; D012680:Sensitivity and Specificity; D013030:Spain