[Small-scale analysis of suspected cancer clusters based on cancer registry data].

Cancer registries collect data about the occurrence and temporal changes of the occurrence of all types of cancer. This information is an important basis for health administration as well as for the evaluation of possible cancer causes. Cancer clusters can be detected by analysis of registry data according to place or district of residence of diseased persons. Cancer registries frequently receive enquiries from concerned citizens asking for investigation of the causes of suspected cancer clusters. The management of suspected cancer clusters can be described as crisis management due to the mixing of medical, biological, political, and psychological factors. In this article, we present an overview of current guidelines and methods for handling suspected cancer clusters by cancer registries. Moreover, the numerical analysis of small-scale cancer registry data is illustrated using two examples from the Bavarian Cancer Registry.