Nicolas Waespe

BACKGROUND Underweight, overweight, and linear growth during and after cancer treatment can impact treatment efficacy and survival in childhood cancer patients, and long-term health in childhood cancer survivors (CCS). However, scientific evidence on the weight status and growth of CCS is limited. Previous studies have been small, focused on specific cancer types, or lacked objectively measured longitudinal data. The availability of standardized, semantically interoperable routine data from oncology clinics offers an unprecedented opportunity to investigate nutritional status across all childhood cancer types, treatment regimens, and critical time windows. OBJECTIVE We will investigate underweight, overweight, and growth trajectories from birth to adulthood in childhood cancer patients and survivors. We will identify predictors associated with distinct growth and weight trajectories and assess the consistency of findings across European countries. METHODS The Growth study will collect routinely recorded sociodemographic, clinical, and anthropometric data from paediatric and adolescent cancer patients (aged <20 years) from Switzerland, Portugal and Slovenia, We will include patients diagnosed between 2004-2026, by linking data from the Swiss Childhood Cancer Registry (ChCR), the Swiss Childhood Cancer Survivor Study (SCCSS), the Swiss Federal Statistical Office (FSO), and oncology clinics in Switzerland. Deterministic linkage of data sources (ChCR, SCCSS, oncology clinics, and FSO) will be performed using social security numbers. We will calculate age- and sex-specific z-scores for weight, height, and BMI based on country-specific and World Health Organization growth references. Latent trajectory modelling will be applied to identify distinct growth and weight trajectories and to detect subgroups at increased risk of growth impairment. We will use logistic regression models to identify predictors of impaired growth. RESULTS The project was funded in 2025; first study results are expected to be published by autumn 2027. We will obtain routinely collected data from approximately 12,250 childhood cancer patients and survivors - 7,800 from Switzerland, 3,350 from Portugal, and 1,100 from Slovenia. CONCLUSIONS The Growth study will provide insights into the nutritional status of childhood cancer patients and survivors and improve understanding of growth patterns in this population. Identifying high risk groups and tumour or treatment related factors will inform targeted surveillance strategies and early nutritional interventions. CLINICALTRIAL ClinicalTrials.gov NCT07750444

Background: Underweight, overweight, and linear growth during and after cancer treatment can impact treatment efficacy and survival in childhood cancer patients, and long-term health in childhood cancer survivors (CCS). However, scientific evidence on the weight status and growth of CCS is limited. Previous studies have been small, focused on specific cancer types, or lacked objectively measured longitudinal data. The availability of standardized, semantically interoperable routine data from oncology clinics offers an unprecedented opportunity to investigate nutritional status across all childhood cancer types, treatment regimens, and critical time windows. Objectives: We will investigate underweight, overweight, and growth trajectories from birth to adulthood in childhood cancer patients and survivors. We will identify predictors associated with distinct growth and weight trajectories and assess the consistency of findings across European countries. Methods: The Growth study will collect routinely recorded sociodemographic, clinical, and anthropometric data from paediatric and adolescent cancer patients (aged <20 years) from Switzerland, Portugal and Slovenia, We will include patients diagnosed between 2004-2026, by linking data from the Swiss Childhood Cancer Registry (ChCR), the Swiss Childhood Cancer Survivor Study (SCCSS), the Swiss Federal Statistical Office (FSO), and oncology clinics in Switzerland. Deterministic linkage of data sources (ChCR, SCCSS, oncology clinics, and FSO) will be performed using social security numbers. We will calculate age- and sex-specific z-scores for weight, height, and BMI based on country-specific and World Health Organization growth references. Latent trajectory modelling will be applied to identify distinct growth and weight trajectories and to detect subgroups at increased risk of growth impairment. We will use logistic regression models to identify predictors of impaired growth. Results: The project was funded in 2025; first study results are expected to be published by autumn 2027. We will obtain routinely collected data from approximately 12,250 childhood cancer patients and survivors - 7,800 from Switzerland, 3,350 from Portugal, and 1,100 from Slovenia. Conclusions: The Growth study will provide insights into the nutritional status of childhood cancer patients and survivors and improve understanding of growth patterns in this population. Identifying high-risk groups and tumour- or treatment-related factors will inform targeted surveillance strategies and early nutritional interventions.

Objective: To map real-world management of paediatric differentiated thyroid carcinoma (DTC) across Europe and identify targets for harmonization. Design: Cross-sectional, web-based survey of centres providing paediatric DTC care. Setting & Participants: One consolidated response per centre was requested from a clinician overseeing paediatric DTC. The instrument covered centre profile/multidisciplinary tumour (MDT) board organization; staging and guideline use; risk stratification and dynamic response; diagnostics; surgery/lymph node management; radioactive iodine therapy (RAIT) policy and activity selection; and thyroid-stimulating hormone targets, follow-up, shared-care/transition. Analyses were descriptive at centre level. Results: Forty-two centres from 18 countries participated in the survey. Response denominators varied by item. Among responding centres, ≈75% were university or academic hospitals, ≈70% used a paediatric age cut-off of ≤18 years, and ≈60% reported having a dedicated MDT board. Staging and guideline use were heterogeneous: centres most often reported mixed or centre-specific guidance, followed by the American Thyroid Association (ATA) 2015 guideline, national guidelines, and the European Thyroid Association (ETA) 2022 guideline. Dynamic response-to-therapy categories were commonly used. For unilateral presumed low-risk disease, hemithyroidectomy was the usual initial surgery in approximately two-thirds to three-quarters of centres, whereas total thyroidectomy was less common. For low-risk patients, RAIT policy were split between de-escalation and risk-adapted use. When administered, RAIT activity was determined using weight-based, dosimetric, or fixed empirical approaches. Country-level patterns suggested clustering around ETA-leaning, ATA-leaning, and national guideline frameworks. Conclusions: Across Europe, centres broadly endorse risk-adapted care but diverge at key decision nodes—extent of surgery, formal risk framework, and RAIT in low-risk disease—reflecting guidance plurality and organizational context. Leveraging existing infrastructures offers pragmatic avenues to reduce unwarranted variation while generating paediatric-specific evidence to refine recommendations.

Rationale: Childhood cancer survivors (CCS) are at risk for long-term pulmonary complications from treatment-related toxicity. Nitrogen multiple breath washout (N2MBW) may detect small airway dysfunction earlier than standard pulmonary function tests (PFTs), but its value in CCS remains uncertain. Objectives: To determine the prevalence of ventilation inhomogeneity measured by N2MBW in CCS, evaluate whether it detects abnormalities beyond spirometry and diffusion capacity for carbon monoxide (DlCO), and explore associations with treatment exposures. Methods: In this prospective multicenter study (Bern, Basel, and Geneva, Switzerland), we measured lung function in CCS aged 6 to 21 years who were undergoing routine follow-up. We stratified participants into high-risk (pulmotoxic chemotherapy [busulfan, bleomycin, nitrosoureas], thoracic surgery, radiotherapy, or hematopoietic stem cell transplantation [HSCT]) and standard-risk (other systemic anticancer treatments). PFTs included N2MBW (lung clearance index [LCI], acinar [SACIN] and conductive [SCOND] inhomogeneity), spirometry (forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC]), and DlCO. Abnormal values were defined as z-score < −1.645 or >1.645, calculated using the Global Lung Initiative references. We quantified the proportion of participants with isolated elevated LCI and analyzed associations with treatment exposures using multivariable linear regression. Results: We included 191 CCS (median 7 years postdiagnosis). Mean LCI was 6.27 (95% CI, 6.17-6.37), with 7% of participants showing abnormal values. N2MBW results did not differ between high- and standard-risk groups, but allogeneic HSCT survivors had the highest mean LCI (7.18 [95% CI, 5.99-8.38]), with 33% abnormal. Survivors had mildly impaired mean FEV1, FVC, and DlCO z-scores (−0.21, −0.34, 0.23), more pronounced in high-risk CCS (−0.67, −0.85, −0.05). Isolated LCI impairment, without abnormalities in spirometry or DlCO, occurred in only 3%. Among treatment exposures, only allogeneic HSCT was associated with higher LCI (1.40 [95% CI, 0.57-2.33]) and SACIN (1.24 [95% CI, 0.20-2.28]). Conclusions: Most pediatric CCS had normal lung function. N2MBW abnormalities were rare, occurring mainly in allogeneic HSCT survivors. Overall, N2MBW added little beyond standard PFTs, suggesting it may not be needed for routine follow-up at this stage, except after allogeneic HSCT. Larger, longitudinal studies should clarify the onset, progression, and prognostic significance of N2MBW abnormalities and their potential role in risk-adapted follow-up care. Clinical Trial Registration: NCT04732273.

Background: Cancer registries are essential to monitor cancer incidence and survival to provide better quality cancer data for research. In Switzerland, the pediatric oncology units within pediatric hospitals actively report cancer cases, and the coding and registration team of the Childhood Cancer Registry (ChCR) enters data manually from medical files into the registry database. There are no automated data transfers or feedback loops between the pediatric oncology clinics and the ChCR. This ongoing process is time-consuming, inefficient, and a source of potential errors. Objective: SwissPedCancer aims to explore the options for automated data transfers from clinical data warehouses and feedback loops to make cancer registry processes more efficient. Methods: SwissPedCancer is a nested project within the national data stream initiative, the Swiss Pediatric Personalized Research Network (SwissPedHealth). Since September 2022, SwissPedHealth has developed and piloted structures to make routine clinical data from pediatric oncology clinics available for monitoring, benchmarking, and research in an interoperable, standardized, and quality-controlled way. SwissPedCancer expects to include approximately 2800 patients diagnosed with cancer before the age of 20 years between 2017 and 2023. The pediatric oncology clinics’ data and the manually validated ChCR data will be delivered separately to a secure national computing network for health-related data (Biomedical Information Technology). We will compare these two data sources to assess completeness (case ascertainment), accuracy (validity), and timeliness of cancer registration in the ChCR. We will evaluate data on diagnosis, treatments, underlying genetic disease, remission, relapse, and late effects. SwissPedCancer will provide a framework for optimizing standardized and uniform data transfers between pediatric oncology clinics and the ChCR and for other registries within Switzerland. Results: The project was funded in September 2022 and received ethics exemption in October 2023. Data extraction from participating hospitals and the ChCR is expected to commence in January 2026. Study results are anticipated to be available in summer 2026. Conclusions: SwissPedCancer aims to reduce manual workload while improving the completeness, accuracy, timeliness, and comparability of childhood cancer data in Switzerland. The project will contribute to a robust, interoperable, and sustainable national infrastructure supporting high-quality cancer registration, timely analyses, and evidence-based decision-making.

Cancer Predisposition Syndromes (CPS) are heritable genetic conditions associated with an increased risk of developing various cancers throughout life. While early identification and tumour surveillance can improve outcomes, CPS are often underdiagnosed in clinical practice. To evaluate clinicians’ perspectives and identify barriers to CPS identification and care across Europe, we conducted the SCOPE study: a three-part cross-sectional survey of paediatric haematology/oncology professionals, followed by a modified Delphi consensus process with members of the SIOP Europe Host Genome Working Group. A total of 185 paediatric oncologists from 22 countries participated in the survey. More than 40% of participants reported low or uncertain confidence across different CPS-related tasks, particularly in counselling families (64.3%) and interpreting germline genetic findings (57.3%). Access to clinical geneticists and dedicated CPS clinics were predictors of higher confidence for some domains, while individual experience and institutional patient volume had limited influence. Regular use of universal CPS screening tools was low (42.3%), with most clinicians relying on personal judgement rather than structured criteria. The most cited barriers were lack of screening guidelines (57%) and difficulties in interpreting results (35.1%). Regular training and workshops, availability of genetic counsellors or educators for patient support, and patient-friendly education material were most cited as areas of improvement. The Delphi process led to three recommendations: (1) improve clinician training and communication strategies, (2) integrate CPS screening into standard treatment plans, and (3) develop accessible, patient-centred educational materials. These recommendations highlight opportunities to enhance CPS care through structured support, interdisciplinary collaboration, and systematic screening approaches.

Rationale: Childhood cancer survivors (CCS) are at risk for long-term pulmonary complications from treatment-related toxicity. Nitrogen multiple-breath washout (N ₂ MBW) may detect small airway dysfunction earlier than standard pulmonary function tests (PFTs), but its value in CCS remains uncertain. Objectives: To determine the prevalence of ventilation inhomogeneity measured by N ₂ MBW in CCS, evaluate whether it detects abnormalities beyond spirometry and diffusion capacity for carbon monoxide (DLCO), and explore associations with treatment exposures. Methods: In this prospective multicenter study (Bern, Basel, Geneva), we measured lung function in CCS aged 6–21 years who were undergoing routine follow-up. We stratified participants into high-risk (pulmotoxic chemotherapy [busulfan, bleomycin, nitrosoureas], thoracic surgery or radiotherapy, or hematopoietic stem cell transplantation [HSCT]) and standard-risk (other systemic anticancer treatments). PFTs included N ₂ MBW (lung clearance index [LCI], acinar [S _ACIN ] and conductive [S _COND ] inhomogeneity), spirometry (forced expiratory volume in 1 second [FEV₁], forced vital capacity [FVC]), and DLCO. Abnormal values were defined as z-score <-1.645 or >1.645, calculated using the Global Lung Initiative references. We quantified the proportion of participants with isolated elevated LCI and analyzed associations with treatment exposures using multivariable linear regression. Results: We included 191 CCS (median 7 years post-diagnosis). Mean LCI was 6.27 (95%CI 6.17–6.37), with 7% abnormal. N ₂ MBW results did not differ between high- and standard-risk groups, but allogeneic HSCT survivors had the highest mean LCI (7.18, 95%CI 5.88–8.37), with 33% abnormal. Survivors had mildly impaired mean FEV ₁ , FVC, and DLCO z-scores (−0.21, −0.34, 0.23), more pronounced in high-risk CCS (−0.67, −0.85, −0.05). Isolated LCI impairment, without abnormalities in spirometry or DLCO, occurred in only 3%. Among treatment exposures, only allogeneic HSCT was associated with higher LCI (1.40, 95%CI 0.57–2.33) and S _ACIN (1.24, 95%CI 0.20–2.28). Conclusion: Most pediatric CCS had normal lung function. N ₂ MBW abnormalities were rare, occurring mainly in allogeneic HSCT survivors. Overall, N ₂ MBW added little beyond standard PFTs, suggesting it may not be needed for routine follow-up at this stage, except after allogeneic HSCT. Larger, longitudinal studies should clarify the onset, progression, and prognostic significance of N ₂ MBW abnormalities and their potential role in risk-adapted follow-up care.

Summary: Aims: Nationwide registration of childhood cancers in Switzerland began in 1976. With the implementation of the Federal Law on Cancer Registration in 2020, cancer registration became compulsory, and methods were standardized nationwide across childhood and adult cancers. This paper describes the objectives and methods of the Childhood Cancer Registry (ChCR) as of 2025 and presents recent data on incidence, mortality and survival of childhood and adolescent cancers in Switzerland. Methods: The ChCR records all primary cancers diagnosed in children and adolescents aged 0–19 years who live in Switzerland. Case reporting is mandatory for physicians, hospitals, and pathology laboratories. Eligible diagnoses include all malignant tumors, tumors of uncertain/unknown behavior, benign central nervous system tumors, histiocytosis, and selected other conditions. Cases are coded primarily according to ICD-10, ICD-O, the International Classification of Childhood Cancer (ICCC), and the Toronto Childhood Cancer Staging Guidelines. The registry collaborates closely with the Swiss Paediatric Oncology Group (SPOG), Cantonal Cancer Registries (CCRs), the National Agency for Cancer Registration (NACR), and the Federal Statistical Office (FSO). We calculated incidence and mortality rates for patients diagnosed between 2014 and 2023 using FSO population statistics and estimated 1-, 5- and 10-year observed survival using the Kaplan-Meier method with the period approach. Results: From 1976 to 2023, 12,665 primary cancers diagnosed in individuals aged 0–19 years were registered. Between 2014 and 2023, 2,441 new cases were diagnosed among children (0–14 years) and an estimated 1,214 among adolescents (15–19 years), adjusting for incomplete regional coverage in adolescents before 2020. In children, the most frequent diagnostic groups were CNS tumors (653, 27%), leukemias (641, 26%) and lymphomas (275, 11%), followed by neuroblastoma, soft tissue sarcomas and other carcinomas and melanomas (all 6%), kidney tumors (5%) and bone tumors (4%). In adolescents, the most common diagnoses were lymphomas (287, 24%), carcinomas and melanomas (277, 23%), and CNS tumors (213, 18%), followed by leukemias (12%) and germ cell tumors (10%). Age-standardized annual incidence per million (standardized to the European Standard Population 2013) was 189 (95% CI 182– 197) in children aged 0–14, and 282 (95% CI 265–299) in those aged 15–19. Overall, five-year survival was 89% for children and 90% for adolescents, with variation across ICCC-3 diagnostic groups. Conclusions: With mandatory reporting and strong collaboration among national stakeholders, the ChCR has evolved into a comprehensive and reliable data source. Its high completeness and long-term follow-up make it a critical resource for epidemiological and clinical research on childhood and adolescent cancers in Switzerland.