title: The EUROCARE-5 study on cancer survival in Europe 1999-2007: Database, quality checks and statistical analysis methods.
abstract: BACKGROUND
  Since 25years the EUROCARE study monitors the survival of cancer patients in Europe through centralised collection, quality check and statistical analysis of population-based cancer registries (CRs) data. The European population covered by the study increased remarkably in the latest round. The study design and statistical methods were also changed to improve timeliness and comparability of survival estimates. To interpret the EUROCARE-5 results on adult cancer patients better here we assess the impact of these changes on data quality and on survival comparisons.
  
  
  METHODS
  In EUROCARE-5 the survival differences by area were studied applying the complete cohort approach to data on nearly nine million cancer patients diagnosed in 2000-2007 and followed up to 2008. Survival time trends were analysed applying the period approach to data on about 10 million cancer cases diagnosed from 1995 to 2007 and followed up to 2008. Differently from EUROCARE-4, multiple primary cancers were included and relative survival was estimated with the Ederer II method.
  
  
  RESULTS
  EUROCARE-5 covered a population of 232 million resident persons, corresponding to 50% of the 29 participating countries. The population coverage increased particularly in Eastern Europe. Cases identified from death certificate only (DCO) were on average 2.9%, range 0-12%. Microscopically confirmed cases amounted to over 85% in most CRs. Compared to previous methods, including multiple cancers and using the Ederer II estimator reduced survival estimates by 0.4 and 0.3 absolute percentage points, on average.
  
  
  CONCLUSIONS
  The increased population size and registration coverage of the EUROCARE-5 study ensures more robust and comparable estimates across European countries. This enlargement did not impact on data quality, which was generally satisfactory. Estimates may be slightly inflated in countries with high or null DCO proportions, especially for poor prognosis cancers. The updated methods improved the comparability of survival estimates between recently and long-term established registries and reduced biases due to informative censoring.
authors.affiliation: Centro Nazionale di Epidemiologia, Sorveglianza e Promozione della Salute, Istituto Superiore di Sanità, viale Regina Elena 299, 00161 Rome, Italy. Electronic address: silvia.rossi@iss.it.
authors.forename: Silvia
authors.initials: S
authors.lastname: Rossi
authors.affiliation: Department of Preventive and Predictive Medicine, Analytical Epidemiology and Health Impact Unit, Fondazione IRCCS, Istituto Nazionale dei Tumori, via Venezian 1, 20133 Milan, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Baili
authors.affiliation: Centro Nazionale di Epidemiologia, Sorveglianza e Promozione della Salute, Istituto Superiore di Sanità, viale Regina Elena 299, 00161 Rome, Italy; Department of Preventive and Predictive Medicine, Evaluative epidemiology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, via Venezian 1, 20133 Milan, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Capocaccia
authors.affiliation: Centro Nazionale di Epidemiologia, Sorveglianza e Promozione della Salute, Istituto Superiore di Sanità, viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Caldora
authors.affiliation: Servizio informatico, documentazione, biblioteca ed attività editoriali, Settore I - Informatica Istituto Superiore di Sanità, viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Carrani
authors.affiliation: Department of Preventive and Predictive Medicine, Analytical Epidemiology and Health Impact Unit, Fondazione IRCCS, Istituto Nazionale dei Tumori, via Venezian 1, 20133 Milan, Italy.
authors.forename: Pamela
authors.initials: P
authors.lastname: Minicozzi
authors.affiliation: Centro Nazionale di Epidemiologia, Sorveglianza e Promozione della Salute, Istituto Superiore di Sanità, viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Pierannunzio
authors.affiliation: Servizio informatico, documentazione, biblioteca ed attività editoriali, Settore I - Informatica Istituto Superiore di Sanità, viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Mariano
authors.initials: M
authors.lastname: Santaquilani
authors.affiliation: Department of Preventive and Predictive Medicine, Evaluative epidemiology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, via Venezian 1, 20133 Milan, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Trama
authors.affiliation: Cancer Research UK Cancer Survival Group, Department of Non-Communicable Disease Epidemiology, London School of Hygiene & Tropical Medicine, Keppel St., London WC1E 7HT, UK.
authors.forename: Claudia
authors.initials: C
authors.lastname: Allemani
authors.affiliation: Cancer Research UK Cancer Survival Group, Department of Non-Communicable Disease Epidemiology, London School of Hygiene & Tropical Medicine, Keppel St., London WC1E 7HT, UK; Service de Biostatistique, Hospices Civils de Lyon, F-69003 Lyon, France; Université de Lyon, F-69000 Lyon, France; Université de Lyon 1, F-69100 Villeurbanne, France; CNRS, UMR5558, Laboratoire de Biométrie et Biologie Evolutive, Equipe Biostatistique-Santé, F-69100 Villeurbanne, France.
authors.forename: Aurelien
authors.initials: A
authors.lastname: Belot
authors.affiliation: Registro Tumori Toscano, Istituto per lo studio e la prevenzione oncologica, Via Cosimo il Vecchio 2, 50141 Florence, Italy.
authors.forename: Carlotta
authors.initials: C
authors.lastname: Buzzoni
authors.affiliation: Foundation National Institute for Cancer Epidemiology and Registration (NICER) c/o University of Zürich, Seilergraben 49, CH-8001 Zürich, Switzerland.
authors.forename: Matthias
authors.initials: M
authors.lastname: Lorez
authors.affiliation: Centro Nazionale di Epidemiologia, Sorveglianza e Promozione della Salute, Istituto Superiore di Sanità, viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: De Angelis
keywords: Cancer; EUROCARE; Europe; Population-based registries; Quality checks; Survival