Why Complete Pediatric Cancer Registration in Germany Requires Cross-Sector Reporting Obligations: A Registry...

Complete, high-quality cancer registration is essential for epidemiological research and evidence generation in children and adolescents, particularly for very rare entities. We compared population-based and pediatric clinical cancer registration in Germany and benchmarked the patterns against U.S. Surveillance, Epidemiology, and End Results data.

We evaluated new cancer diagnoses in individuals younger than 18 years (2010-2022) from the German Center for Cancer Registry Data, the German Childhood Cancer Registry, and the U.S. Surveillance, Epidemiology, and End Results (SEER) program. As completeness varied by federal statse, German Center for Cancer Registry Data analyses focused on Baden-Württemberg and Bavaria. Age-standardized incidence rates were calculated using Segi World Standard Population.

The German Center for Cancer Registry Data contained 27,425 new diagnoses (Baden-Württemberg and Bavaria: 8,366), the German Childhood Cancer Registry 30,051 (Baden-Württemberg and Bavaria: 8,747), and the U.S. Surveillance, Epidemiology, and End Results program 92,707. The overall incidence rates per 1,000,000 were 162.1 (German Center for Cancer Registry Data Baden-Württemberg and Bavaria), 174.4 (German Childhood Cancer Registry Baden-Württemberg and Bavaria), and 205.8 (U.S. Surveillance, Epidemiology, and End Results). Between the German Center for Cancer Registry Data and the German Childhood Cancer Registry, incidence rates for Baden-Württemberg and Bavaria diverged markedly for leukemias (41.1 vs. 52.5), central nervous system tumors (36.0 vs. 39.4) and epithelial malignancies (13.1 vs. 6.2). Age patterns showed a stronger contribution of late adolescence to epithelial entities in German Center for Cancer Registry Data and data from the U.S. Surveillance, Epidemiology, and End Results program.

We identified substantial discrepancies and under-ascertainment in pediatric cancer registration in Germany compared with the U.S. Surveillance, Epidemiology, and End Results data. Existing registries capture partly different segments of the pediatric cancer spectrum, with large gaps for adolescent epithelial malignancies. Improved completeness and cross-sector case ascertainment are needed for robust epidemiological research and evidence-informed, age-adapted care recommendations, especially for very rare pediatric tumors.