Introduction
Advances in diagnosis and treatment of childhood cancer over the last decades have dramatically increased long-term survival, with a 5-year overall survival of more than 80%.1 As a result, the number of childhood cancer survivors is growing and it has become increasingly clear that the former disease and its treatment can significantly impair long-term (psychosocial) health leading also to premature mortality.2-5
In 2010 the Dutch Childhood Cancer Survivor Study (DCCSS) LATER collaborative group finalized the LATER guideline for surveillance of late effects in survivors of childhood cancer and identified clinically-relevant gaps in knowledge.6 The DCCSS group of clinicians, researchers, and representatives from the patient-parent organization designed the DCCSS LATER cohort study, currently consisting of 2 parts (Figure 1). In the LATER 1 observational study, outcomes on health conditions were collected, through questionnaires and linkages to national registries. The methods for this study have been described in a separate paper.(Teepen et al. Joint submission with current manuscript)
Here we describe the methodology and first results of the second wave of health outcome measurements, the so-called LATER 2 study, which involves clinical measurements.
All cohort members alive in 2016 were invited to participate in this cross-sectional study, the backbone of which consists of the periodic guideline-based regular care visit to the late effects outpatient clinic.
The goals of the LATER 2 study are A) to identify and characterize populations at high risk for medical and/or psychosocial chronic health conditions associated with childhood cancer, its treatment, and other risk factors such as lifestyle, B) to identify accurate screening tests for adverse health outcomes in survivors of childhood cancer, C) to get insight into the pathophysiological mechanisms and genetic predisposition underlying the multi-factorial etiology of the studied health outcomes, D) to identify groups of survivors who may benefit from interventions and preventive measures and to identify subgroups who will likely not benefit from such actions.
To achieve these goals, the DCCSS LATER study group designed, a priori, 16 sub-studies based on health outcomes (Supplemental information Table 1). Eligible survivors were invited to undergo diagnostic tests and questionnaires for research purposes, in addition to the diagnostic tests during regular care, based on the LATER guidelines. This paper describes the methodological aspects of the overall LATER 2 study; clinical visit & questionnaire study. The specific methodologies of sub-studies will be described in separate papers.