There exist population-based cancer registries and hospital cancer registries (also called hospital-based cancer registries).
Population-based cancer registries monitor the frequency (so-called incidence) of cancer diseases between regions and over time by collecting case reports from different sources (clinicians and pathologists). If an unexpected accumulation can be observed a hypothesis about possible causes is generated. This hypothesis is investigated in a second step by collecting more detailed data. The aim is to recognize and to reduce risks. Population-based registries can also monitor the effects of preventive measures.
Hospital cancer registries aim at the improvement of cancer therapy. Therefore they have to collect detailed data about diagnosis and therapy. Improvements can be achieved by:
Since the data needed by hospital cancer registries usually include those of population-based cancer registries and both use the same classifications data can be sent from a hospital cancer registry to a population-based registry thus reducing documentation efforts.
Hospital and Population-based cancer registries report their incidence data to national organizations that aggregate and publish the data. The way in which these data are formatted to be submitted to these organizations are determined by standards released by standard-setting organizations. Edits are run on the data to check for inaccuracies and duplicate cases before being submitted electronically. Different organizations have different standards for data reliability and completeness, and some award certifications based on the adherence to these standards.