People who overcome cancer diagnosed during childhood may have more health issues later in life than their peers. Therefore, many childhood cancer survivors may need specialized surveillance to avert or limit the adverse consequences of their cancer treatment. With the overall improvement of the results of cancer treatment, the number of childhood cancer survivors is growing. To ensure that adequate care is available for these people, it is essential to know how many childhood cancer survivors there are.
The number of survivors in a country at a specific date is called the prevalence. This number can be computed by simply counting all survivors in a registry at a given date, if the registry has data for the entire life span of the registered patients. However, registries with shorter registration periods must use statistical models to estimate the prevalence of the patients who were diagnosed with childhood cancer before the start of the registry. This involves assumptions about the number of cases diagnosed and the number of those patients who have survived during the years preceding the registration activity. All methods require information collected by population-based cancer registries. These registries record agreed data on all cancers occurring in the populations they cover.
This review summarizes published information on the prevalence of childhood cancer survivors in Europe. From an initial list of 979 published studies that mentioned prevalence, only 12 were found to report data on the prevalence of childhood cancer survivors in Europe. Because these studies estimated the prevalence of survivors using different methods, different time periods, and different ages of survivors, the prevalence estimates ranged from 450 to 1240 people in 1 million people of the same age and sex. The specific prevalence of survivors of an embryonal tumour was estimated in 6 studies and ranged from 48 to 95 people in 1 million.
This review showed that the prevalence of childhood cancer survivors in Europe has not been studied systematically, and reporting of estimates was not standard. The large variations in the estimated numbers of cancer survivors observed in the reviewed studies have sprung from differences in the availability of relevant data, the selection of the target population for the estimates, the method used to estimate the prevalence, the time period considered, the date at which the prevalence was estimated, and other factors. The authors believe that standard methodology of estimating the prevalence of childhood cancer survivors and presentation of the results in the same way for all countries would enable direct comparisons and help quantify the needs of childhood cancer survivors across Europe.
The full publication, led by researchers of the International Agency for Research on Cancer (IARC) in collaboration with Cancer Council Queensland (Australia), the National Cancer Registration and Analysis Service (United Kingdom), and the CRICCS Consortium, is available at https://doi.org/10.1016/j.ejcped.2024.100155.