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.
CONCLUSIONS: 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.

A 10-year-old boy presented with a right flank mass. Computed tomography, ultrasound scan, and magnetic resonance imaging confirmed the presence of a multiloculated cystic mass. After right kidney nephrectomy, the biopsy proved the diagnosis of cystic renal cell carcinoma, which is a rare subtype of renal cell carcinoma in the pediatrics age group. The knowledge about this incidence can optimize the investigations, management, and outcomes.

In Sudan, the survival of Wilms tumour was reported as 11% in a 2008 study. The impact of establishing paediatric oncology service on survival is studied, and the obstacles of treating Wilms tumour patients were identified.
This study investigates Wilms tumour treatment outcomes over 10 years at Khartoum Oncology Hospital (KOH).
All Wilms tumour patients from 2005 to 2014 were analysed retrospectively. Patients received treatment based on the NWTS IV protocol. Patients were analysed for overall survival, and event-free survival and these outcomes were correlated with age, sex, stage at presentation, and histology.
We analysed 143 files of Wilms tumour patients. The male to female ratio is 1.75. The mean age of patients at diagnosis is 3.5 years. The follow-up period is 5 years. Most patients (83%) had advanced disease stage 3, and 4. There is a very high abandonment rate 61 (42.6%). The event-free survival among patients who completed treatment is 75.6%, and is 43.4% for all the (143) patients.
\"After initiation of the paediatric oncology service, the survival of Wilms tumour in Sudan is 43%. Abandonment of treatment remains high. Opportunity remains to reduce abandonment and establish a surgical paediatric oncology service to improve outcomes further.\"

Aim: This study aimed to analyze clinical characteristics and image findings in patients initially diagnosed with renal masses and treated on the Société Internationale d\'Oncologie Pédiatrique (SIOP) 2001 protocol for Wilms tumor (WT) that eventually were diagnosed with different pathologies. Methods: We reviewed the preoperative symptoms, laboratory tests, and images of patients who were initially treated for WT and proved to have other diagnoses. Data from these patients were compared to those of the last 10 patients with WT and the last 10 patients with neuroblastoma (NBL) treated at a single institution. Results: From June 2001 to December 2020, we treated 299 patients with NBL and 194 with WT. Five patients treated with preoperative chemotherapy for WT were postoperatively diagnosed with NBL (one patient had bilateral renal masses and one with multifocal xanthogranulomatous pyelonephritis). Three underwent nephrectomy, two biopsies only, and one adrenalectomy due to intraoperative characteristics. Regarding clinical presentation, abdominal mass or swelling was very suggestive of WT (p = 0.011); pain, although very prevalent in the study group (67%), was not statistically significant, as well as intratumoral calcifications on computed tomography (CT) (67%). Urinary catecholamines were elevated in all patients mistreated for WT with the exception of the patient with pyelonephritis in which it was not collected. Conclusion: Some pathologies can be misdiagnosed as WT, especially when they present unspecified symptoms and dubious images. Diagnostic accuracy was 98.1%, which highlights the quality of the multidisciplinary team. Abdominal mass or swelling is highly suggestive of WT, especially in the absence of intratumoral calcifications on CT. If possible, urinary catecholamines should be collected at presentation as they help in the differential diagnosis of NBL.

UNASSIGNED: Renal tumors in children are treated according to the guidelines of the Renal Tumor Study Group of the International Society of Pediatric Oncology (SIOP-RTSG). Nephroblastoma is the most frequent renal tumor in children.
UNASSIGNED: After sonography, magnetic resonance imaging (MRI) is the preferred imaging modality. The task of imaging includes differential diagnosis with the help of morphological and epidemiological criteria. Thorax computed tomography (CT) is introduced for initial staging.
UNASSIGNED: Current studies of diffusion-weighted imaging (DWI)-MRI with analysis of the apparent diffusion coefficient (ADC) histogram indicate the potential to differentiate blastemal or anaplastic high-risk histology nephroblatoma subtypes. Imaging criteria for nephron-sparing surgery are defined and allow an individual therapy option in unilateral and especially in bilateral renal nephroblastoma.
UNASSIGNED: In addition to nephroblastoma, the differential diagnosis includes congenital mesoblastic nephroma, malignant rhabdoid tumor of the kidney, clear cell sarcoma and renal cell carcinoma. The diagnosis of nephrogenic rests and nephroblastomatosis is challenging.
UNASSIGNED: Diagnostic standardization improves diagnosis and therapy of renal childhood tumors, and new prognostic markers may be introduced in the near future.
UNASSIGNED: KLINISCHES/METHODISCHES PROBLEM: Nierentumoren im Kindesalter werden nach Vorgaben der Renal Tumor Study Group der Internationalen Gesellschaft für pädiatrische Onkologie (RTSG-SIOP) behandelt. Der häufigste renale Tumor im Kindesalter ist das Nephroblastom.
UNASSIGNED: Die Magnetresonanztomographie (MRT) ist nach der Sonographie die bevorzugte bildgebende Methode. Die Aufgabe der Bildgebung umfasst die Differenzialdiagnose renaler Tumoren im Kindesalter anhand epidemiologischer und morphologischer Kriterien. Neu ist die Einführung der Thorax-Computertomographie (CT) in der initialen Diagnostik.
UNASSIGNED: Neue Studien zu Nephroblastomsubtypen mit Diffusionsbildgebung (DWI) zeigen, dass durch Auswertungen des ADC(„apparent diffusion coefficient“)-Histogramms blastemreiche und anaplastische High-risk-Tumoren zu differenzieren sind. Bildgebende Kriterien zur nierenerhaltenden chirurgischen Therapie sind aktuell festgelegt und erlauben eine individuelle Therapie bei unilateralen, aber insbesondere bei bilateralen Tumoren. LEISTUNGSFäHIGKEIT: Differenzialdiagnosen sind neben dem kongenitalen mesoblastischen Nephrom, der Rhabdoidtumor, das Klarzellsarkom und das Nierenzellkarzinom. Herausfordernd ist die Diagnose nephrogener Reste und der Nephroblastomatose.
UNASSIGNED: Durch standardisierte Bildgebung verbessert sich Diagnostik und Therapie renaler Tumoren im Kindesalter, und neue prognostische Marker können zukünftig in der Bildgebung etabliert werden.

Definitions of nephron-sparing surgery (NSS) procedures in Wilms tumor (WT) are not clear. The new UMBRELLA protocol offers a formula (NSS(X)-SRM(n)-PRM(n)-RRP(n%)) to better define the different NSS parameters. We aimed to assess the advantages and limits of this new formula.
This retrospective monocentric study included patients operated by NSS for WT from 1975 to 2018. We reviewed the medical records and applied the NSS formula to all included patients.
Eighty kidneys were operated on 56 patients at a mean age of 19.2 months (4 days-7.5 years), with 49 partial nephrectomies and 31 tumorectomies. The assessment of the surgical resection margins (SRM) showed a doubt in six cases and one tumor breach. An intact pseudocapsule along the resection margin with no renal parenchyma was found in four cases at pathological resection margins (PRM) assessment, whereas a tumor breach was described in seven cases. Among the six patients with a surgical doubt, only one had a pathological stage III. There were no surgical doubts in the seven patients with tumor breach at pathology. At a mean follow-up of eight years (15 days-28.6 years), eight patients had elevated blood pressure levels. Ten had proteinuria. These two parameters were significantly increased in patients with a remaining renal parenchyma (RRP) of less than half of the initial total renal parenchyma. The serum creatinine level was normal for all except two patients.
The new NSS formula described all the crucial elements of NSS. RRP seemed essential for the evaluation of long-term renal function.

High-risk (HR) metastatic (stage IV) Wilms tumours (WTs) have a particular poor outcome.
Here, we report the results of HR (diffuse anaplastic [DA] or blastemal type [BT]) stage IV WT treated patients according to the HR arm in the SIOP2001 prospective study.
From January 2002 to August 2014, 3559 patients with WT were included in the SIOP2001 trial. Among the 525 patients (15%) with metastatic WT, 74 (14%) had stage IV HR-WT. The median age at diagnosis was 5.5 years (range: 1.4-18.3). Thirty-four patients (47%) had BT-WT and 40 (53%) had DA-WT. Five-year event-free survival rates were 44 ± 17% and 28 ± 15% for BT-WT and DA-WT, respectively (p = 0.09). Five-year overall survival rates were 53 ± 17% and 29 ± 16% for BT-WT and DA-WT, respectively (p = 0.03). Metastatic complete response after preoperative treatment was significantly associated with outcome in univariate and multivariate analyses (hazards ratio = 0.3; p = 0.01). Postoperative radiotherapy of metastatic sites might also be beneficial. Forty-three of 74 patients experienced a relapse or progression predominantly in the lungs (80%). The median time to relapse/progression after diagnosis was 7.3 months (range: 1.6-33.3) and 4.9 months (range: 0.7-28.4) for BT-WT and DA-WT, respectively (p = 0.67). This is the first prospective evidence of inferior survival of stage IV BT-WT as compared with historical intermediate-risk WT. Survival of patients with stage IV DA-WT has not improved compared to the previous SIOP93-01 study.
These results call for new treatment approaches for patients with HR stage IV WT.

To evaluate feasibility and outcomes of minimally invasive surgery (MIS) in Wilms tumor (WT).
International multicenter review of MIS total nephrectomies for WT between 2006 and 2018. Medical records of confirmed WT were retrospectively assessed for demographic, imaging, treatment, pathology, and oncological outcome data.
Fifty patients, with a median age of 38 months (6-181), were included in 10 centers. All patients received neoadjuvant chemotherapy, as per SIOP protocol. Median tumor volume post-chemotherapy was 673 mL (18-3331), 16 tumors crossed the lateral border of the spine, and three crossed the midline. Six patients with tumors that crossed the lateral border of the spine (tumor volumes 1560 mL [299-2480]) were converted to an open approach. There was no intraoperative tumor rupture. Overall, MIS was completed in 19% of the 195 nephrectomies for WT presenting during the study period. Tumor was stage I in 29, II in 16, and III in 5, and histology was reported as low in three, intermediate in 42, and high risk in five. Three patients had positive tumor margins. After a median follow-up of 34 months (2-138), there were two local recurrences (both stage I, intermediate risk, 7 and 9 months after surgery) and one metastatic relapse (stage III, high risk, four months after surgery). The three-year event-free survival was 94%.
MIS is feasible in 20% of WT, with oncological outcomes comparable with open surgery, no intraoperative rupture, and a low rate of local relapse. Ongoing surveillance is, however, needed to evaluate this technique as it becomes widespread.

Favorable histology (FH) Wilms tumor (WT) is one of the most curable of all human cancers, yet a small minority of patients fail treatment. The underlying biological pathways that lead to therapy resistance are unknown. We report a case of initially unresectable, FH WT which revealed limited necrosis and persistent blastemal predominant histology following neoadjuvant chemotherapy. Despite intensification of therapy and whole abdominal radiation, the patient relapsed and succumbed to her disease. In an effort to discover candidate drivers of drug resistance, whole exome sequencing and copy number analysis were performed on samples from all 3 tumor specimens. Sequencing results revealed outgrowth of clones with a dramatically different genetic landscape including dominant mutations that could explain therapy evasion, some of which have not been previously reported in WT. Our results implicate PPM1D, previously shown to be associated with drug resistance in other tumors, as the major driver of treatment failure.

Hepatoblastoma and Wilms tumor are the most common primary liver and kidney tumor in children, respectively, and little is documented about patient outcomes in the immediate perioperative period. The aim of this study was to analyze the short-term outcomes of pediatric patients after surgical resection for hepatoblastoma and Wilms tumor.
We queried the 2012-2016 ACS National Surgical Quality Improvement Program-Pediatric (NSQIP-P) database for patients with hepatoblastoma who underwent liver resection and patients with Wilms tumor who underwent a partial or total nephrectomy. Patient demographics, preoperative, intraoperative, and postoperative characteristics were analyzed. Multivariate logistic regression was used to determine independent risk factors for unplanned reoperations.
There were a total of 189 patients with hepatoblastoma and 586 patients with Wilms in National Surgical Quality Improvement Program-Pediatric. The mean age of patients with hepatoblastoma was 3.1 y and 4.2 y in the Wilms group. Nine percent (n = 17) of patients underwent an unplanned reoperation after hepatectomy, and 4.1% (n = 24) of patients with Wilms experienced an unplanned reoperation. Over half of patients with hepatoblastoma (59.8%, n = 113) and 29.7% (n = 174) patients with Wilms tumor received a blood transfusion in the perioperative period. Patients in both groups demonstrated low rates of surgical site infections, but 6.3% (n = 12) of hepatoblastoma patients showed evidence of sepsis.
This study will allow providers to more effectively counsel families of the common morbidities in the associated perioperative period following surgical resection of either solid tumor type including the substantial risk of blood transfusion.