Database

The ACCIS database contains:

• Listings of individual records of all primary cancers diagnosed in the residents of well-defined registration areas in Europe since 1970, in patients younger than 20 years at diagnosis
• Records of all subsequent primary tumours in these patients, irrespective of the age of their occurrence
• Relevant population data
• Coding dictionaries
• Comments on individual datasets.

The current ACCIS database, completed at the end of 2017, contains:

• Data from 110 population-based cancer registries (paediatric and general)
• 2.6 billion person-years at risk of developing cancer before the age of 20 years
• 370 000 cases of incident cancer in patients younger than 20 years at diagnosis, including multiple tumours of these patients that occurred at a later age.

All datasets included in the database were centrally validated in collaboration with the contributing registries. Individual records were automatically verified and classified using ad hoc internal software based on the IARC/IACR tools [2] and ICD-O-3 [3]. Tumours were classified according to the International Classification of Childhood Cancer [9]. Registries were asked to respond to questions about the cancer incidence patterns and time trends observed in their data, their registration practices, and mutual data exchange. Population data were also examined for consistency. All datasets were approved as comparable by the members of the ACCIS Scientific Committee.

Subsets of the ACCIS database may be analysed and interpreted in a number of publications.