title: The incidence of renal cancer in Polish National Cancer Registry: is there any epidemiological data we can rely on?
abstract: BACKGROUND
  The Polish National Cancer Registry (KRN) is the most commonly used sources of data on the incidence of cancers including renal cancer in Poland. Until today, the accuracy and completeness of these data has never been verified.
  
  
  METHODS
  The aim of this study was to assess the completeness and reliability of data on the incidence of renal cancer published by the KRN. KRN data on newly diagnosed cases of renal cancer in Poland (for the whole country) and separately in subjectively selected provinces between 2009 and 2011 were retrospectively compared to the data received from the National Health Fund (NFZ) on the number of radical and partial nephrectomies performed due to renal cancer in the same time frame and regions.
  
  
  RESULTS
  The concordance between the analysed two sources of data was 86%. Calculated ratio of the number of cases in the KRN database to number of cases in the NFZ database in selected provinces were as follows: 109% in Lubuskie, 60% in Mazowieckie, 123% in Podkarpackie and 66% in Podlaskie. No significant differences were observed between analyzed years (89% in 2009, 88% in 2010, 82% in 2011). The number of unreported cases of renal cancer in KRN was lower among male patients comparing to female patients (concordance: 78% vs. 72%).
  
  
  CONCLUSIONS
  The incidence of renal cancer published by KRN is underestimated, thus KRN does not seem to be a fully reliable source of epidemiological data. Due to the fact that this data is crucial for the planning of the health policy in Poland, improving urooncological reporting should be a priority for the health system managers.
authors.affiliation: Department of General, Oncological and Functional Urology, Medical University of Warsaw, Poland.
authors.forename: Piotr Zygmunt
authors.initials: PZ
authors.lastname: Wojcieszak
authors.affiliation: Department of General, Oncological and Functional Urology, Medical University of Warsaw, Poland.
authors.forename: Sławomir
authors.initials: S
authors.lastname: Poletajew
authors.affiliation: Department of Healthcare Services, National Health Fund, Warsaw, Poland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Rutkowski
authors.affiliation: Department of General, Oncological and Functional Urology, Medical University of Warsaw, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Radziszewski
keywords: Polish National Cancer Registry; cancer registries; data completeness; renal cancer