Single-cell transcriptomics identifies aberrant glomerular angiogenic signalling in the early stages of WT1 kidney disease.

WT1 encodes a podocyte transcription factor whose variants can cause an untreatable glomerular disease in early childhood. Although WT1 regulates many podocyte genes, it is poorly understood which of them are initiators in disease and how they subsequently influence other cell-types in the glomerulus. We hypothesised that this could be resolved using single-cell RNA sequencing (scRNA-seq) and ligand-receptor analysis to profile glomerular cell-cell communication during the early stages of disease in mice harbouring an orthologous human mutation in WT1 (Wt1R394W/+). Podocytes were the most dysregulated cell-type in the early stages of Wt1R394W/+ disease, with disrupted angiogenic signalling between podocytes and the endothelium, including the significant downregulation of transcripts for the vascular factors Vegfa and Nrp1. These signalling changes preceded glomerular endothelial cell loss in advancing disease, a feature also observed in biopsy samples from human WT1 glomerulopathies. Addition of conditioned medium from murine Wt1R394W/+ primary podocytes to wild-type glomerular endothelial cells resulted in impaired endothelial looping and reduced vascular complexity. Despite the loss of key angiogenic molecules in Wt1R394W/+ podocytes, the pro-vascular molecule adrenomedullin was upregulated in Wt1R394W/+ podocytes and plasma and its further administration was able to rescue the impaired looping observed when glomerular endothelium was exposed to Wt1R394W/+ podocyte medium. In comparative analyses, adrenomedullin upregulation was part of a common injury signature across multiple murine and human glomerular disease datasets, whilst other gene changes were unique to WT1 disease. Collectively, our study describes a novel role for altered angiogenic signalling in the initiation of WT1 glomerulopathy. We also identify adrenomedullin as a proangiogenic factor, which despite being upregulated in early injury, offers an insufficient protective response due to the wider milieu of dampened vascular signalling that results in endothelial cell loss in later disease. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Multimodality detection of tumour rupture in children with Wilms tumour.

BACKGROUND AND AIMS: Tumour rupture (TR) signifies stage III disease and requires treatment intensification, which includes radiotherapy. We studied the associations between radiological, surgical and pathology TR in children with Wilms tumour (WT) in a United Kingdom multicentre clinical study. PATIENTS AND METHODS: The IMPORT (Improving Population Outcomes for Renal Tumours of Childhood) study registered 712 patients between 2012 and 2021. Children with TR on central radiology review (CRR) at diagnosis and/or indication of preoperative TR on surgical forms were included. Correlation between radiology/surgery/pathology findings was made. RESULTS: Total 141 patients had TR identified (69 on CRR, 43 on surgical form and 29 on both), and 124/141 had images available for CRR, and 98/124 had features suggestive of TR on diagnostic CRR (63 magnetic resonance imaging/35 computed tomography). TR was limited to the renal fossa in 47/98 (48%) and intraperitoneal in 51/98 (52%). Three of 98(3%) had upfront surgery, and 87/95 (92%) had TR confirmed on post-chemotherapy preoperative scans. Among 80/98 (82%) cases with TR on CRR and available surgical forms, TR was not confirmed on surgery or pathology in 38/80, giving a false-positive rate of 48%. Preoperative TR was indicated on 72 surgical forms, with images available for CRR in 55. Twenty-six of 55 (47%) were false-negative for TR on CRR and of those 10/26 (38%) had TR confirmed on pathology. CONCLUSIONS: Radiology alone should not be used to define TR, as it does not accurately correlate with surgical or pathology findings, and therefore cannot be relied upon for definitive staging and treatment. A multidisciplinary team should take the decision regarding the final abdominal stage and treatment using a multimodality approach considering clinical, radiological, surgical and pathological findings.

Prevalence of childhood cancer survivors in Europe: a scoping review.

Childhood cancer survivors (CCS) require specialized follow-up throughout their lifespan to prevent or manage late effects of cancer treatment. Knowing the size and structure of the population of CCS is crucial to plan interventions. In this scoping review we reviewed studies that reported prevalence of CCS in Europe. We searched Medline, Web of Science, and Embase using permutations of terms referring to childhood, cancer, survivors, prevalence, registries, and Europe. We followed PRISMA-ScR guidelines to select studies and The Joanna Briggs Institute Prevalence Critical Appraisal Tool to evaluate their quality. From 979 unique studies published between 1989 and 2022, 12 were included. Limited-duration prevalence (LDP) for all childhood cancers, assessed in three studies using counting method, varied between 450 and 1240 persons per million. Complete prevalence (CP) of survivors of any childhood cancer except skin carcinomas, reported in three studies using observed data complemented with modelled data for the unobserved period, varied between 730 and 1110 persons per million. CP of survivors of an embryonal tumour was estimated by completeness index method in six studies. In four of them CP ranged from 48 to 95 persons per million for all embryonal tumours, while CP for those occurring in central nervous system was 43 per million in one study and CP for rhabdomyosarcoma was 17 per million in another. Information on prevalence of CCS in Europe is fragmented and inconsistent. The large variations in LDP and CP estimates were linked to differences in data availability, the selection of populations, prevalence measure, statistical method, incidence period, index date, age at diagnosis and prevalence, cancer types, sex, and, for LDP, also the length of follow-up. Standardisation of methodology and reporting are needed to systematically monitor and compare CCS prevalence in Europe and provide data to help address survivors' needs.

Surgical aspects and outcomes after nephrectomy for Wilms tumour in sub-Saharan Africa: A report from Wilms Africa Phase II-CANCaRe Africa.

BACKGROUND: Wilms tumour (WT) is one of the common and curable cancer types targeted by the Global Initiative for Childhood Cancer. Tumour excision is essential for cure. This analysis focuses on surgical outcomes of patients with WT in sub-Saharan Africa. METHODS: We implemented a risk-stratified WT treatment guideline as a multicentre, prospective study across eight hospitals and six countries. Eligibility criteria were age 6 months to 16 years, unilateral WT, surgery performed after preoperative chemotherapy and diagnosed between 1 January 2021 and 31 December 2022. Data collection included a specific surgical case report form (CRF). RESULTS: The study registered 230 patients, among whom 164 (71.3%) had a nephrectomy. Ninety-eight percent of patients had a completed surgical CRF. Out 164 patients, 50 (30.5%) had distant metastases. Median tumour diameter at surgery was 11.0 cm. Lymph node sampling was done in 122 (74.3%) patients, 34 (20.7%) had intraoperative tumour rupture, and for 18 (10.9%), tumour resection involved en bloc resection of another organ. Tumour size at surgery was significantly correlated with tumour rupture (p < .01). With a median follow-up of 17 months (range: 2-33), 23 (14.0%) patients have relapsed. Twenty-two (13.4%) patients abandoned treatment post nephrectomy. Two-year event-free survival was 60.4% ± 4.7% with treatment abandonment as an event. CONCLUSION: Survival post nephrectomy is challenged by treatment abandonment, treatment-related mortality and relapse. Large tumours after preoperative chemotherapy were associated with a higher risk of tumour rupture. Earlier diagnosis and access to radiotherapy are expected to improve survival.

Prevention of treatment abandonment remains an important challenge to increase survival of Wilms tumor in sub-Saharan Africa: A report from Wilms Africa-CANCaRe Africa.

BACKGROUND: The Wilms Africa studies implemented an adapted Wilm's tumor (WT) treatment protocol in sub-Saharan Africa in two phases. Phase I began with four sites and provided out-of-pocket costs. Phase II expanded the number of sites, but lost funding provision. Objective is to describe the outcomes of Phase II and compare with Phase I. METHODS: Wilms Africa Phase I (n = 4 sites; 2014-2018) and Phase II (n = 8 sites; 2021-2022) used adapted treatment protocols. Funding for families' out-of-pocket costs was provided during Phase I but not Phase II. Eligibility criteria were age less than 16 years and newly diagnosed unilateral WT. We documented patients' outcome at the end of planned first-line treatment categorized as treatment abandonment, death during treatment, and disease-related events (death before treatment, persistent disease, relapse, or progressive disease). Sensitivity analysis compared outcomes in the same four sites. RESULTS: We included 431 patients in Phase I (n = 201) and Phase II (n = 230). The proportion alive without evidence of disease decreased from 69% in Phase I to 54% in Phase II at all sites (p = .002) and 58% at the original four sites (p = .04). Treatment abandonment increased overall from 12% to 26% (p < .001), and was 20% (p = .04) at the original four sites. Disease-related events (5% vs. 6% vs. 6%) and deaths during treatment (14% vs. 14% vs. 17%) were similar. CONCLUSION: Provision of out-of-pocket costs was important to improve patient outcomes at the end of planned first-line treatment in WT. Prevention of treatment abandonment remains an important challenge.

Estimation of the optimal radiotherapy utilization rate for childhood neuroblastoma.

BACKGROUND AND PURPOSE: The optimal utilization rate of radiotherapy (oRUR) serves as a benchmark for assessing service demand and improving access to cancer care. While it is estimated that approximately 50 % of adult cancer patients require external beam radiotherapy during their treatment, there is a scarcity of data regarding the optimal use of radiotherapy in pediatric cancer. In this study, we adopted an established method and developed a model to estimate the oRUR in childhood neuroblastoma. MATERIALS AND METHODS: We developed a decision tree model to calculate the oRUR using indications for radiotherapy and corresponding epidemiological data collected through systematic review and meta-analysis. Sensitivity analyses were performed to evaluate the impact of variations in radiotherapy indications between treatment protocols and variables in the model. We calculated and compared the oRUR for global, high-income, and low- and middle-income settings. RESULTS: The oRUR for pediatric neuroblastoma was 64 % (95 % CI: 58 %-71 %) in the global setting, 50 % in high-income countries, and 68 % in low- and middle-income countries. The impact of variation in radiotherapy indications between major international treatment protocols was negligible. CONCLUSION: The knowledge of oRUR is crucial for evaluating current practices, identifying gaps in access, and planning future radiotherapy services for treating childhood cancer. Based on our results, 64 % of children with neuroblastoma have an indication for radiotherapy. Patients in low- and middle-income countries have more indications for radiotherapy than those in high-income countries, due to a more adverse tumour stage distribution caused by limited access to healthcare resources.

Corrigendum: Cancer data quality and harmonization in Europe: The experience of the BENCHISTA Project - International Benchmarking of Childhood Cancer Survival by Stage.

[This corrects the article DOI: 10.3389/fonc.2023.1232451.].

The role of International Society of Paediatric Oncology (SIOP) in advancing global childhood cancer care.

The Société Internationale d'Oncologie Pédiatrique [International Society of Paediatric Oncology] (SIOP), founded in 1969, aims to improve the lives of children and adolescents with cancer through global collaboration, education, training, research and advocacy. The annual congress provides the opportunity to share late-breaking research, clinical experiences and debate, with experts worldwide. SIOP's six Continental Branches represent their constituent members in North America, Oceania, Latin America, Africa, Europe and Asia and bring best practices and recent research findings of value to their specific patient populations. In 1990, the SIOP Board of Directors addressed the formerly predominantly European/North American society transforming into a global association by establishing a scholarship program to bring low- and middle-income country (LMIC) paediatric oncologists and nurses to SIOP meetings. A major achievement was SIOP's acceptance as a World Health Organisation (WHO) non-state actor in official relations in 2018, joining 220 non-governmental organisations, international business associations and philanthropic foundations with this privilege. SIOP supports advocacy with WHO member states and civil society to highlight the specific needs of cancer in this age-group through key programs especially supporting the WHO Global Initiative for Childhood Cancer. Sustained improvement in childhood cancer outcomes has paralleled the integration of research with care; thus, SIOP launched a Programme for Advancing Research Capacity for funding selected clinical trial groups in LMICs. SIOP supports south-south partnerships, and the principles elegantly expressed in SIOP Africa's checklist for co-branding projects, that include the prioritisation of local needs, cultivation of local expertise and commitment to equitable partnerships. SIOP now counts approximately 3,000 members from over 128 countries; 39% are from more than 60 LMICs. SIOP members have multidisciplinary expertise on all aspects of childhood cancer care working in collaboration with key stakeholders including governments, civil society organisations and funders to improve the lives of children/adolescents with cancer everywhere in all ways.

Omission of adjuvant chemotherapy in patients with completely necrotic Wilms tumor stage I and radiotherapy in stage III: The 30-year SIOP-RTSG experience.

BACKGROUND: Completely necrotic Wilms tumor (CN-WT) following preoperative chemotherapy has been regarded as low-risk WT since the International Society of Paediatric Oncology (SIOP) 93-01 study, and patients have been treated with reduced postoperative therapy. The aim of the study was to evaluate whether the omission of adjuvant chemotherapy in patients with localized CN-WT stage I and radiotherapy in stage III was safe. PATIENTS AND METHODS: The retrospective observational study of outcomes of patients diagnosed with localized CN-WT on central pathology review and treated according to the SIOP 93-01 and SIOP-WT-2001 protocols (1993-2022). RESULTS: There were 125 patients with localized CN-WT: 90 with stage I, 10 with stage II, and 25 with stage III. Sixty-two of 125 (49.6%) patients had a discrepant diagnosis and/or staging between the institutional pathologist and central pathology review. In the group of 90 patients with stage I, postoperative chemotherapy was not given to 41 (46%) patients, whereas 49 patients received postoperative chemotherapy-in the latter group, two patients relapsed, and one of them died. One stage I and one stage II patient developed chemotherapy-induced toxicity and died. Nineteen of 25 patients with stage III received no flank radiotherapy. No stage III patient relapsed or died. The overall 5-year event-free survival (EFS) estimate for the entire cohort (stages I-III) was 96.8% [95% confidence interval, CI: 93.6%-99.6%] and the overall survival (OS) was 97.6% [95% CI: 95.0-100%]. The EFS and OS were 97% and 98%, respectively, for stage I, and 100% for stage III. CONCLUSION: Omission of postoperative chemotherapy for patients with CN-WT stage I, and radiotherapy for stage III is safe. Rapid central pathology review is required to assign appropriate treatment and avoid treatment-related side effects.

TRIM28 inactivation in epithelial nephroblastoma is frequent and often associated with predisposing TRIM28 germline variants.

Wilms tumors (WTs) are histologically diverse childhood cancers with variable contributions of blastema, stroma, and epithelia. A variety of cancer genes operate in WTs, including the tripartite-motif-containing-28 gene (TRIM28). Case reports and small case series suggest that TRIM28 mutations are associated with epithelial morphology and WT predisposition. Here, we systematically investigated the prevalence of TRIM28 inactivation and predisposing mutations in a cohort of 126 WTs with >2/3 epithelial cells, spanning 20 years of biobanking in the German SIOP93-01/GPOH and SIOP2001/GPOH studies. Overall, 44.4% (56/126) cases exhibited loss of TRIM28 by immunohistochemical staining. Of these, 48 could be further analyzed molecularly, revealing TRIM28 sequence variants in each case - either homozygous (~2/3) or heterozygous with epigenetic silencing of the second allele (~1/3). The majority (80%) of the mutations resulted in premature stops and frameshifts. In addition, we detected missense mutations and small deletions predicted to destabilize the protein through interference with folding of key structural elements such as the zinc-binding clusters of the RING, B-box-2, and PHD domains or the central coiled-coil region. TRIM28-mutant tumors otherwise lacked WT-typical IGF2 alterations or driver events, except for rare TP53 progression events that occurred with expected frequency. Expression profiling identified TRIM28-mutant tumors as a homogeneous subset of epithelial WTs that mostly present with stage I disease. There was a high prevalence of perilobar nephrogenic rests, putative precursor lesions, that carried the same biallelic TRIM28 alterations in 7/7 cases tested. Importantly, 46% of the TRIM28 mutations were present in blood cells or normal kidney tissue, suggesting germline events or somatic mosaicism, partly supported by family history. Given the high prevalence of predisposing variants in TRIM28-driven WT, we suggest that immunohistochemical testing of TRIM28 be integrated into diagnostic practice as the management of WT in predisposed children differs from that with sporadic tumors. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.