title: A novel approach to estimate the German-wide incidence of testicular cancer.
abstract: BACKGROUND
  Currently, only 7 out of 16 Federal States of Germany provide testicular cancer incidence rates with an estimated completeness of at least 90% which complicates the regional comparison of incidence rates. The aim of this study was to provide a novel approach to estimate the testicular cancer incidence in Germany by using nationwide hospitalization data.
  
  
  METHODS
  We used the nationwide hospitalization data (DRG statistics) of the years 2005-2006 including 16,6 million hospitalizations among men. We identified incident testicular cancer cases by the combination of a diagnosis of testicular cancer and an orchiectomy during the same hospitalization and estimated the age-specific and age-standardized (World Standard Population) incidence of testicular cancer across Federal States. We also analyzed available cancer registry data from 2005 to 2006.
  
  
  RESULTS
  A total of 8544 hospitalizations indicated incident testicular cancer cases in 2005-2006. The nationwide crude incidence rate of testicular cancer was 10,6 per 100.000 person-years. The ratio of the number of registered cases (cancer registry) to the estimated number of cases based on the hospitalization statistics ranged between 79% and 100%. There was only little variation of the age-standardized DRG-based incidence estimates across Federal States (range: 8,2-10,6 per 100.000 person-years).
  
  
  CONCLUSIONS
  We provided testicular cancer incidence estimates for each of the 16 Federal States of Germany based on hospitalization data for the first time. The low within-population incidence variability in Germany and high between-population incidence variability in Europe may indicate that ecologic factors play a causal role in the European variation of testicular cancer.
authors.affiliation: Institute of Clinical Epidemiology, Medical Faculty, Martin-Luther-University of Halle-Wittenberg, Magdeburger Str. 8, 06097 Halle, Germany. andreas.stang@medizin.uni-halle.de <andreas.stang@medizin.uni-halle.de>
authors.forename: Andreas
authors.initials: A
authors.lastname: Stang
authors.forename: Alexander
authors.initials: A
authors.lastname: Katalinic
authors.forename: Klaus-Peter
authors.initials: KP
authors.lastname: Dieckmann
authors.forename: Ron
authors.initials: R
authors.lastname: Pritzkuleit
authors.forename: Roland
authors.initials: R
authors.lastname: Stabenow
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005858:Germany / Q000453:epidemiology; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D013736:Testicular Neoplasms / Q000453:epidemiology*; D055815:Young Adult