[The 41,000 long-term survivor cohort of the German Childhood Cancer Registry]. / Die Kohorte der 41.000 Langzeitüberlebenden des Deutschen Kinderkrebsregisters.

BACKGROUND AND OBJECTIVES: One-third of childhood cancer long-term survivors suffer from severe late effects (e.g., secondary cancer and cardiovascular diseases). The German Childhood Cancer Registry (GCCR) holds approximately 70,000 registered cancer cases, of which more than 41,000 are long-term survivors, with recent follow-up and contact information that can be used for scientific studies on late effects. The characteristics of this cohort are presented, previous late effects studies with the support of the GCCR are described, and the respective participation rates are reported. METHODS: For all patients who developed cancer between 1980 and 2019 and were in long-term observation at the GCCR, the distribution of diagnoses, current age, observation time, and number of secondary cancers as of 16 July 2021 was determined. The rates of patients who responded to history queries were computed. The influence of determinants on the participation rate were calculated using generalized estimating equations. RESULTS: The cohort comprises 41,466 long-term survivors. Of these, 10% are older than 40 years and 40% had their cancer diagnosis more than 20 years ago. The participation rates range between 30 and 60% and depend on age at diagnosis, the complexity of the study, and the number of previously conducted surveys. A time interval of at least four years between two consecutive contacts seems optimal. CONCLUSIONS: Our unique cohort enables population-based research on late effects after childhood cancer. To define a sensible time interval for contacting survivors is essential. In order to ensure that survivors are not contacted too frequently, the number of survivors included in research projects should be as small as possible.

Impact of the COVID-19 pandemic on incidence, time of diagnosis and delivery of healthcare among paediatric oncology patients in Germany in 2020: Evidence from the German Childhood Cancer Registry and a qualitative survey.

BACKGROUND: The indirect impact of the COVID-19 pandemic on cancer care and timely diagnosis is of increasing concern. We investigated the impact of the COVID-19 pandemic on incidence, time of diagnosis and delivery of healthcare among paediatric oncology patients in Germany in 2020. METHODS: We analysed incident paediatric cancer cases diagnosed in 0- to 17-year olds in Germany in 2020 using data of the German Childhood Cancer Registry. Absolute numbers and age-standardised incidence rates (ASR) in 2020 were compared to the previous five years (2015-2019). Moreover, we conducted a survey with open-ended questions, gathering perceptions of the diagnostic process and healthcare delivery for paediatric oncology patients during the COVID-19 pandemic. FINDINGS: More or similar numbers of paediatric cancer patients were newly diagnosed each month throughout 2020 in comparison to the previous five years. The estimated ASRs showed markedly higher incidence rates, overall and across diagnostic groups, in 2020 compared to 2015-2019. Results from the qualitative survey indicated that diagnostic processes, timeliness of diagnosis, and delivery of treatment were hardly affected during the COVID-19 pandemic. However, psychosocial supportive care and non-urgent appointments were considerably reduced during the lockdown periods. INTERPRETATION: We found no indications of severe adverse effects of the COVID-19 pandemic on diagnosis and delivery of healthcare among children with cancer in Germany. The underlying reasons of the increase in incidence rates remain speculative. Continued close monitoring of incidence patterns may shed light on the underlying reasons of the present increase and contribute to understanding disease aetiology. FUNDING: None.