Survivors of childhood cancer need specialized medical care. Knowing how many survivors need medical attention at a given time helps to plan health-care provision.
Information needed to calculate the number of survivors is collected by cancer registries. The longer the period over which a registry collected data in a defined area, the more precise the estimates of the numbers of survivors will be. The most precise information would be derived from records of individual patients followed up over their lifetime, although few registries have operated for such a long time.
In addition, the new General Data Protection Regulation in the European Union makes it difficult or impossible to share information on individual patients. Therefore, it is impossible to count the number of patients with cancer who were diagnosed as children and need medical care years after their diagnosis.
This study developed a method of estimating the number of childhood cancer survivors that works with aggregated data. Aggregated data are not subject to data protection regulations, because identification of individuals is impossible.
The new method was tested using the records of the Netherlands Comprehensive Cancer Organisation. The method estimated that there were 5380 male and 4523 female survivors of childhood cancer diagnosed in 2001-2011, living in The Netherlands in 2011. These estimated numbers correspond closely with the numbers of survivors counted when individual cancer records were used.
Although it is preferable to use individual cancer records to obtain exact counts of survivors, this new method enables the comparison of numbers of survivors despite incomplete data in many European countries, and thus helps to determine the demands on medical care of survivors of childhood cancers.
The full publication, led by researchers of the International Agency for Research on Cancer (IARC) in collaboration with Cancer Council Queensland (Australia), the National Disease Registration Service, NHS England (United Kingdom), and the Netherlands Comprehensive Cancer Organisation, is available at https://doi.org/10.1093/ije/dyad124.