Data sources

High-quality data play a vital role in assessing cancer epidemiology; the following data sources are mainly used in the Czech Republic.

Czech National Cancer Registry: incidence, prevalence and mortality data

The main source of data on cancer epidemiology is the Czech National Cancer Registry (CNCR), which is part of the National Health Information System (NHIS). CNCR is a population-based registry that records cancer cases and periodically monitors their further development. CNCR provides aggregate data for statistical surveys on both national and international levels, as well as data for epidemiological studies and health research. CNCR data are also used to support early diagnosis and treatment of cancers and pre-cancerous conditions and to monitor trends in their incidence, causative factors and societal implications. Cancer registration is enshrined in Czech legislation and is obligatory. The administrator of CNCR is the Institute of Health Information and Statistics of the Czech Republic (IHIS CR) [1].

Today, CNCR is an integral part of comprehensive cancer care, containing more than 3 million records from 1977–2022. The following diseases from the group of neoplasms are subject to mandatory reporting (according to the International Statistical Classification of Diseases and Associated Health Problems, 10. Revision – hereafter referred to as ICD-10): malignant neoplasms (C00–C97), neoplasms in situ (D00–D09), neoplasms of uncertain or unknown behaviour (D37-D48) and selected non-malignant/benign neoplasms with morphology 8683/0 gangliocytic paraganglioma or 8936/0 gastrointestinal stromal tumour - benign. In total, 2,810,967 malignant neoplasms (coded as C00–C97 according to ICD-10), 164,923 neoplasms in situ (D00–D09, monitored in CNCR since 1979), and 59,429 neoplasms of uncertain and unknown behaviour (D37–D48, monitored in CNCR since 1987) were registered in the Czech Republic as of 31 December 2022.

Reporting has shown a partial decrease in the number of newly diagnosed cancers in 2020 and 2021 due to the COVID-19 pandemic. This is partly due to the high number of excess deaths, especially in the elderly population during the COVID-19 pandemic; however, some diagnostic groups have also shown a decrease in the number of new diagnoses due to the lack of preventive and screening examinations during the pandemic. From 2022 onwards, a return to the original upward trend has been observed.

The Czech National Cancer Registry has undergone a significant change in reporting methodology since 2019: data collection has been completely converted to direct electronic reporting by health services providers.

Czech Statistical Office: demographic and mortality data by cause of death

The Czech Statistical Office (CSO) processes data on its demographic structure to monitor the Czech population's current state and continuous development. These data cover the main demographic characteristics, especially the number of inhabitants, age structure, life expectancy, etc. [2]. The source of data on population-based cancer-related mortality in the Czech Republic is primarily the so-called Death Records Database, which the CSO methodically processes according to international rules based on data from death certificates [3]. The deceased is assigned one main cause of death, and official statistical outputs on population mortality by cause of death are then processed from these data.

Another possible source of information on cancer mortality is the CNCR. Until 2018, data on causes of death from death certificates were also recorded for individual records of persons and validated according to the recorded cancer diagnoses (ICD-10 diagnosis codes: Dx Ia - diagnosis of the disease that directly led to death / immediate cause of death, Dx Ic - diagnosis of the underlying/main disease / primary cause of death, Dx II - diagnosis of other serious concomitant disease). From these data, it is also possible to determine the specific mortality of each cancer according to the diagnoses listed in Dx Ia or Dx Ic.

References

1. Institute of Health Information and Statistics of the Czech Republic. National Health Information System (NHIS), Czech National Cancer Registry (CNCR), [cited 28 November 2019]. Available (in Czech language only) from: http://www.uzis.cz/nor.
2. Czech Statistical Office. Demographic Handbook 2016, [cited 29 November 2019]. Available (in Czech language only) from: https://www.czso.cz/csu/czso/demograficka-prirucka-2016.
3. Institute of Health Information and Statistics of the Czech Republic. National Health Information System (NHIS), Death Certificate Information System [cited 2019 Nov 29]. Available (in Czech language only) from: http://www.uzis.cz/lpz.