The Swiss Childhood Cancer Survivor Study - Follow-up (SCCSS-FollowUp)

Background: Survival after childhood cancer has increased substantially over the last decades. In Switzerland, 10-year survival now exceeds 85%. This results in increasing numbers of childhood cancer survivors - estimated 6,600 survivors currently in Switzerland. Due to the cancer treatment or the cancer itself, a large part of the childhood cancer survivors suffer from late effects. As survivors of childhood cancer have decades of life ahead, it is of special interest to minimize potentially avoidable chronic diseases, impaired quality of life, deaths, and health care costs. There is a need to assess clinical data prospectively in a standardized way across clinics to study late effects on a national level. Such data are currently not available in Switzerland and the SCCSS-FollowUp aims to fill this gap.

Objectives: The SCCSS-FollowUp assesses the prevalence of late effects through risk-adapted medical examinations (in accordance with international guidelines and evidence), identifies CCS with asymptomatic late effects through functional testing, e.g. echocardiography or lung function testing, standardizes clinical follow-up examinations in CCS in Switzerland, and collects follow-up data in a longitudinal way. The SCCSS-FollowUp also investigates sociodemographic, treatment, lifestyle, and clinical risk factors for late effect development.

Methods: The SCCSS-FollowUp recruits eligible childhood cancer survivors in a stepwise approach by identifying CCS at risk because of specific treatment modalities (e.g. exposure to anthracyclines or thoracic irradiation). The investigators ask eligible survivors for participation. Those who consent receive before or during the next follow-up visits focused questionnaires. The questionnaires are short and focus on one organ system, but participants can receive different questionnaires at subsequent visits. The data generated during the follow-up visits, such as clinical examination, functional and laboratory test results, and the completed questionnaires are entered in the SCCSS-FollowUp database. The examinations and tests are performed in a standardized way in all participating clinics and according to follow-up guidelines or other evidence-based literature.

Rationale and significance:

The data collected within the SCCSS-FollowUp allow research on late effects on a national level and based on objective clinical data obtained during routine care. The SCCSS-FollowUp helps to learn more about late effects, especially subclinical damage, which are not detectable by questionnaire only. Early detection of these late effects and timely treatment can prevent and mitigate further deterioration. Furthermore, the SCCSS-FollowUp helps to assess risk factors for late effects development which can be used to amend cancer treatment in future patients. The SCCSS-FollowUp thus helps to improve the health of current and future childhood cancer survivors.

• Symptoms of organ-specific late effects (example of pulmonary late effects) [Time frame: 1 year after recruitment, 2 years after recruitment, 3 years after recruitment, 4 years after recruitment, 5 years after recruitment, 10 years after recruitment, 15 years after recruitment, 20 years after recruitment]
• Signs of organ-specific late effects (example of pulmonary late effects) [Time frame: 1 year after recruitment, 2 years after recruitment, 3 years after recruitment, 4 years after recruitment, 5 years after recruitment, 10 years after recruitment, 15 years after recruitment, 20 years after recruitment]
• Tests to assess organ-specific late effects (example of pulmonary late effects) [Time frame: 1 year after recruitment, 2 years after recruitment, 3 years after recruitment, 4 years after recruitment, 5 years after recruitment, 10 years after recruitment, 15 years after recruitment, 20 years after recruitment]
• Treatment-related risk factors for late effects [Time frame: At baseline]
• Sociodemographic and socioeconomic characteristics potentially associated with late effects [Time frame: At baseline, 1 year after recruitment, 2 years after recruitment, 3 years after recruitment, 4 years after recruitment, 5 years after recruitment, 10 years after recruitment, 15 years after recruitment, 20 years after recruitment]
• Lifestyle factors potentially associated with late effects [Time frame: At baseline, 1 year after recruitment, 2 years after recruitment, 3 years after recruitment, 4 years after recruitment, 5 years after recruitment, 10 years after recruitment, 15 years after recruitment, 20 years after recruitment]
• Comorbidities potentially associated with late effects [Time frame: At baseline, 1 year after recruitment, 2 years after recruitment, 3 years after recruitment, 4 years after recruitment, 5 years after recruitment, 10 years after recruitment, 15 years after recruitment, 20 years after recruitment]