Background Childhood cancer survivors face late health problems; despite advances in research, details on risk remain unclear. We describe the methodological aspects of the Dutch Childhood Cancer Survivor Study (DCCSS) cross-sectional clinical study (LATER 2 study). Procedure From the multi-center DCCSS LATER cohort of 6,165 five-year survivors diagnosed 1963-2001, we invited 4,735 eligible in 2016, as well as siblings and parents of survivors. Gaps in evidence identified during development of surveillance guidelines were translated into clinical research questions for 16 outcome-specific sub-projects. The regular care visit to the LATER outpatient clinic forms the backbone of outcome assessment complemented with research-defined measurements (physical examination, diagnostic tests, questionnaires). Furthermore, blood/saliva samples were taken for DNA extraction. Results In total, 2519 (53.2%) survivors participated in the LATER 2 study. Of those participating survivors, 49.3% was female. Median time since childhood cancer diagnosis was 26.9 years (range 14.8 to 54.7 years) and median attained age was 34.4 years (range 15.4 to 66.6 years). Conclusions The high-quality data generated in the LATER 2 study will provide valuable insights into risks of and risk factors for clinical and (psychosocial) health outcomes and factors for early recognition of (psychosocial) health outcomes in long-term childhood cancer survivors. This will contribute to fill in important gaps in knowledge and improve the quality of life and care for childhood cancer survivors.

We compared psychosocial functioning of children with cancer and their caregivers in several phases of the COVID-19 pandemic to before COVID-19. One or more questionnaires on health-related quality of life (HRQoL) or fatigue of children or distress of their caregivers was available from 1644 families. In children with cancer, HRQoL was stable throughout the COVID-19 pandemic. Fatigue was slightly lower and sleep somewhat better during the pandemic than before. Caregiver distress was lower in the first pandemic phase, but increased to pre-COVID-19 levels in later phases, indicating that the length and consequences of the pandemic may be weighing on them.

We studied the psychosocial impact of the start of the COVID-19 pandemic on Dutch children with cancer in outpatient care and their caregivers (n=799) using regular monitoring and screening outcomes. No differences were observed between the pre-COVID-19 and COVID-19 era in health-related quality of life and fatigue of children. Fewer caregivers were distressed during the COVID-19 era than pre-COVID-19. In conclusion, the additional stress of COVID-19 did not deteriorate psychosocial functioning of children with cancer and their caregivers. Results may be explained by alleviating daily life changes, experience in coping with medical traumatic stress and appropriate care and support.