Clinical features, treatment, and outcomes of bilateral Wilms' tumor: A systematic review and meta-analysis

Automation of Wilms' tumor segmentation by artificial intelligence

BACKGROUND

3D reconstruction of Wilms' tumor provides several advantages but are not systematically performed because manual segmentation is extremely time-consuming. The objective of our study was to develop an artificial intelligence tool to automate the segmentation of tumors and kidneys in children.

METHODS

A manual segmentation was carried out by two experts on 14 CT scans. Then, the segmentation of Wilms' tumor and neoplastic kidney was automatically performed using the CNN U-Net and the same CNN U-Net trained according to the OV2ASSION method. The time saving for the expert was estimated depending on the number of sections automatically segmented.

RESULTS

When segmentations were performed manually by two experts, the inter-individual variability resulted in a Dice index of 0.95 for tumor and 0.87 for kidney. Fully automatic segmentation with the CNN U-Net yielded a poor Dice index of 0.69 for Wilms' tumor and 0.27 for kidney. With the OV2ASSION method, the Dice index varied depending on the number of manually segmented sections. For the segmentation of the Wilms' tumor and neoplastic kidney, it varied respectively from 0.97 to 0.94 for a gap of 1 (2 out of 3 sections performed manually) to 0.94 and 0.86 for a gap of 10 (1 section out of 6 performed manually).

CONCLUSION

Fully automated segmentation remains a challenge in the field of medical image processing. Although it is possible to use already developed neural networks, such as U-Net, we found that the results obtained were not satisfactory for segmentation of neoplastic kidneys or Wilms' tumors in children. We developed an innovative CNN U-Net training method that makes it possible to segment the kidney and its tumor with the same precision as an expert while reducing their intervention time by 80%.

Cancer predisposition signaling in Beckwith-Wiedemann Syndrome drives Wilms tumor development

BACKGROUND

Wilms tumor (WT) exhibits structural and epigenetic changes at chromosome 11p15, which also cause Beckwith-Wiedemann Syndrome (BWS). Children diagnosed with BWS have increased risk for WT. The aim of this study is to identify the molecular signaling signatures in BWS driving these tumors.

METHODS

We performed whole exome sequencing, methylation array analysis, and gene expression analysis on BWS-WT samples. Our data were compared to publicly available nonBWS data. We categorized WT from BWS and nonBWS patients by assessment of 11p15 methylation status and defined 5 groups- control kidney, BWS-nontumor kidney, BWS-WT, normal-11p15 nonBWS-WT, altered-11p15 nonBWS-WT.

RESULTS

BWS-WT samples showed single nucleotide variants in BCORL1, ASXL1, ATM and AXL but absence of recurrent gene mutations associated with sporadic WT. We defined a narrow methylation range stratifying nonBWS-WT samples. BWS-WT and altered-11p15 nonBWS-WT showed enrichment of common and unique molecular signatures based on global differential methylation and gene expression analysis. CTNNB1 overexpression and broad range of interactions were seen in the BWS-WT interactome study.

CONCLUSION

While WT predisposition in BWS is well-established, as are 11p15 alterations in nonBWS-WT, this study focused on stratifying tumor genomics by 11p15 status. Further investigation of our findings may identify novel therapeutic targets in WT oncogenesis.

Identification of common candidate genes and pathways for Spina Bifida and Wilm's Tumor using an integrative bioinformatics analysis

Spina Bifida (SB) and Wilm's Tumor (WT) are conditions, both associated with children. Several studies have shown that WT later develops in SB patients, which led us to elucidate common key genes and linked pathways of both conditions, aimed at their concurrent therapeutic management. For this, integrated bioinformatics analysis was employed. A comprehensive manual curation of genes identified 133 and 139 genes associated with SB and WT, respectively, which were used to construct a single protein-protein interaction (PPI) network. Topological parameters analysis of the network showed its scale-free and hierarchical nature. Centrality-based analysis of the network identified 116 hubs, of which, 6 were called the key genes attributed to being common between SB and WT besides being the hubs. Gene enrichment analysis of the 5 most essential modules, identified important biological processes and pathways possibly linking SB to WT. Additionally, miRNA-key gene-transcription factor (TF) regulatory network elucidated a few important miRNAs and TFs that regulate our key genes. In closing, we put forward TP53, DICER1, NCAM1, PAX3, PTCH1, MTHFR; hsa-mir-107, hsa-mir-137, hsa-mir-122, hsa-let-7d; and YY1, SOX4, MYC, STAT3; key genes, miRNAs and TFs, respectively, as the key regulators. Further, MD simulation studies of wild and Glu429Ala forms of MTHFR proteins showed that there is a slight change in MTHFR protein structure due to Glu429Ala polymorphism. We anticipate that the interplay of these three entities will be an interesting area of research to explore the regulatory mechanism of SB and WT and may serve as candidate target molecules to diagnose, monitor, and treat SB and WT, parallelly.Communicated by Ramaswamy H. Sarma.

Wilms tumor treatment protocol compliance and the influence on outcomes for children in Tanzania

BACKGROUND

Standardized Wilms tumor treatment protocols exist for low- and middle-income countries, but outcomes equivalent to high-income countries are not achieved outside of clinical trials. As Wilms tumor treatment protocols in Africa shift with increasing resource capacity, it is not known how treatment compliance to each stage of therapy affects outcomes and where the critical breakpoints are for protocol adherence in clinical practice.

PROCEDURE

We describe both treatment outcomes and treatment protocol adherence in a retrospective single-center cohort study of pediatric Wilms tumor patients at a zonal cancer referral hospital in Tanzania from 2016 to 2019, treated per the International Society of Paediatric Oncology standard (2016-2017) or Tanzania adapted (2018-2019) therapy protocols.

RESULTS

A total of 69 patients were evaluated. The two-year overall survival and event-free survival rates were 40% and 29%, respectively. Only 29% of patients completed recommended chemotherapy per protocol, and completion of preoperative and postoperative chemotherapy was predictive of two-year overall survival (odds ratio [OR] 14.4, p < .001). There were delays at almost every stage of treatment, especially time from preoperative chemotherapy to surgery (56 days), from surgery to pathology report (30 days), and from surgery to initiation of postoperative chemotherapy (38 days).

CONCLUSIONS

Nonadherence with recommended Wilms tumor treatment guidelines due to key health system delays correlated to reduced overall survival rates, with chemotherapy nonadherence due to abandonment, lack of surgery, and deaths on therapy as the strongest contributors. Future interventions targeting health system delays and reducing deaths during therapy are critical to improving protocol compliance and increasing overall survival for pediatric Wilms tumor patients in low-resource settings.

Robotic approach with neoadjuvant chemotherapy in adult Wilms' tumor: A feasibility study report and a systematic review of the literature

Objective

The incidence of Wilms' tumor (WT) among adult individuals accounts for less than 1% of kidney cancer cases, with a prognosis usually less favorable when compared to younger individuals and an overall survival rate of 70% for the adult patients versus 90% for the pediatric cases. The diagnosis and treatment of WT are complex in the preoperative setting; neoadjuvant chemotherapy (NAC) or robotic surgery has rarely been described. This study aimed to review the literature of robotic surgery in WT and report the first adult WT management using both NAC and robotic strategy.

Methods

We reported a case of WT managed in a multidisciplinary setting. Furthermore, according to Preferred Reporting Items for Systematic reviews and Meta-Analyses recommendations, a systematic review of the literature until August 2020 of WT treated with a robotic approach was carried out.

Results

A 33-year-old female had a diagnosis of WT. She was scheduled to NAC, and according to the clinical and radiological response to a robotic radical nephrectomy with aortic lymph nodes dissection, she was managed with no intraoperative rupture, a favorable surgical outcome, and a follow-up of 25 months, which did not show any recurrence. The systematic review identified a total number of 230 cases of minimally invasive surgery reported in the literature for WT. Of these, approximately 15 patients were carried out using robotic surgery in adolescents while none in adults. Moreover, NAC has not been administered before minimally invasive surgery in adults up until now.

Conclusion

WT is a rare condition in adults with only a few cases treated with either NAC or minimally invasive approach so far. The advantage of NAC followed by the robotic approach could lead to favorable outcomes in this complex scenario. Notwithstanding, additional cases of adult WT need to be identified and investigated to improve the oncological outcome.

Outcomes according to treatment using an established protocol in patients with bilateral Wilms' tumor: A national Canadian population-based study

BACKGROUND

Bilateral Wilms tumor (BWT) is a rare entity. The goal of this study is to report outcomes (overall and event-free survival, OS/EFS) of BWT in a large cohort representative of the Canadian population since 2000. We focused on the occurrence of late events (relapse or death beyond 18 months), as well as outcomes of patients treated following the only protocol specifically designed for BWT to date, AREN0534, compared to patients treated following other therapeutic schemes.

METHODS

Data was obtained for patients diagnosed with BWT between 2001 and 2018 from the Cancer in Young People in Canada (CYP-C) database. Demographics, treatment protocols, and dates for events were collected. Specifically, we examined outcomes of patients treated according to the Children's Oncology Group (COG) protocol AREN0534 since 2009. Survival analysis was performed.

RESULTS

57/816 (7%) of patients with Wilms tumor had BWT during the study period. Median age at diagnosis was 2.74 years (IQR 1.37-4.48) and 35 (64%) were female; 8/57 (15%) had metastatic disease. After a median follow-up of 4.8 years (IQR 2.8-5.7 years, range 0.2-18 years), OS and EFS were 86% (CI 73-93%) and 80% (CI 66-89%), respectively. Less than 5 events were recorded after 18 months from diagnosis. Since 2009, patients treated according to the AREN0534 protocol had a statistically significant higher OS compared to patients treated with other protocols.

CONCLUSIONS

In this large Canadian cohort of patients with BWT, OS and EFS compared favorably to the published literature. Late events were rare. Patients treated according to a disease-specific protocol (AREN0534) had improved overall survival.

TYPE OF STUDY

Original article.

LEVEL OF EVIDENCE

Level IV.

Bilateral Renal Tumors in Children: The First 5 Years' Experience of National Centralization in The Netherlands and a Narrative Review of the Literature

Survival of unilateral Wilms tumors (WTs) is exceeding 90%, whereas bilateral WTs have an inferior outcome. We evaluated all Dutch patients with bilateral kidney tumors, treated in the first five years of national centralization and reviewed relevant literature. We identified 24 patients in our center (2015–2020), 23 patients had WT/nephroblastomatosis and one renal cell carcinoma. Patients were treated according to SIOP-RTSG protocols. Chemotherapy response was observed in 26/34 WTs. Nephroblastomatosis lesions were stable (n = 7) or showed response (n = 18). Nephron-sparing surgery was performed in 11/22 patients undergoing surgery (n = 2 kidneys positive margins). Local stage in 20 patients with ≥1 WT revealed stage I (n = 7), II (n = 4) and III (n = 9). Histology was intermediate risk in 15 patients and high risk in 5. Three patients developed a WT in a treated nephroblastomatosis lesion. Two of 24 patients died following toxicity and renal failure, i.e., respectively dialysis-related invasive fungal infection and septic shock. Genetic predisposition was confirmed in 18/24 patients. Our literature review revealed that knowledge is scarce on bilateral renal tumor patients with metastases and that radiotherapy seems important for local stage III patients. Bilateral renal tumors are a therapeutic challenge. We describe management and outcome in a national expert center and summarized available literature, serving as baseline for further improvement of care.

Synchronous bilateral Wilms' tumor with liver metastasis

Background

Wilms’ tumor (nephroblastoma) is mostly unilateral; however, bilateral Wilms’ tumors are seen in about 5–8% of patients. This can be synchronous or metachronous. It is uncommon to get liver metastasis from bilateral Wilms’ tumor.

Case presentation

An 8-year-old male Ugandan presented with a history of abdominal swelling and flank pains for 1 year. There was no history of hematuria. Both ultrasound and computed tomography of the abdomen demonstrated multiple solid lesions in both kidneys and a huge solid mass in segments V, VI, VII and VIII of the liver. Histological examination of renal biopsy specimen was favorable for chemotherapeutic regimens. However, following a multidisciplinary tumor board consensus, a nephron-sparing surgery was deemed unsuitable, and he was managed conservatively with chemotherapy (adriamycin and vincristine) with a palliative intent.

Conclusions

Metastatic bilateral Wilms’ tumor has a particularly poor prognosis. There are no clear evidence-based guidelines for the management of this rare presentation. This patient benefited from early palliative care and symptom management.

3D reconstruction of Wilms' tumor and kidneys in children: Variability, usefulness and constraints

INTRODUCTION

Wilms' tumor (WT) is the most common type of malignant kidney tumor in children. Three-dimensional reconstructions can be performed pre-operatively to help surgeons in the planning phase.

OBJECTIVES

The main objective of this study was to determine the variability of WT segmentation and 3D reconstruction. The secondary objectives were to assess the usefulness of these 3D reconstructions in the surgical planning phase and in the selection of patients for nephron-sparing surgery (NSS).

METHODS

14 scans from 12 patients were manually or semi-automatically segmented by 2 teams using 3D Slicer software. Inter-individual variability of 3D reconstructions was measured based on the Dice index. The utility of 3D reconstructions for the surgical planning was evaluated by 4 pediatric surgeons using a 5-point Likert scale. The possibility of undertaking NSS was evaluated according to the criteria defined in the Umbrella SIOP-RTSG 2016 protocol.

RESULTS

Segmentation of the WT, healthy kidney, pathological kidney, arterial and venous vascularization could be performed for all of the patients in this study. Urinary cavities segmentation could only be performed for 5 out of 14 scans that had a delayed acquisition phase. The mean time required to carry out these segmentations was 8.6 h [3-15 h]. The mean Dice index for all of the scans was good (mean: 0.87; range [0.83-0.91]). Considering each anatomical structure, the Dice index was very good for the WT (mean: 0.95; range [0.91-0.97]) and the healthy kidney (mean: 0.95; range [0.93-0.96]), good for the pathological kidney (mean: 0.87; range [0.69-0.96]) and arterial vascularization (mean: 0.84; range [0.74-0.91]). The Dice index was lower than 0.8 for venous vascularization only (mean: 0.77; range [0.58-0.86]). All the surgeons who were interviewed agreed that the 3D reconstructions were realistic representations and useful for the surgical planning phase. The images reconstructed in 3D allowed most of the criteria defined by the Umbrella SIOP-RTSG 2016 protocol to be evaluated regarding the selection of patients who could benefit from NSS.

CONCLUSION

The inter-individual variability of 3D reconstructions of WT is acceptable. Three-dimensional representation appears to assist surgeons with the surgical planning phase by allowing them to better anticipate the operative risks. 3D reconstructions can also be an additional tool to better select patients for NSS. However, the manual or semi-automatic method used is very time-consuming, making it difficult for a routinely use. Developing techniques to automate this segmentation process, therefore, appears to be essential if surgeons and radiologists are to use it in daily practice.