Outcome of Wilms tumor patients with bone metastasis enrolled on National Wilms Tumor Studies 1-5: A report from the Children's Oncology Group

Anaplastic sarcoma of the kidney (DICER1-sarcoma of the kidney): A report from the International Pleuropulmonary Blastoma/DICER1 Registry

BACKGROUND

Anaplastic sarcoma of the kidney (ASK) is a DICER1-related neoplasm first identified as a distinctive tumor type through the evaluation of unusual cases of putative anaplastic Wilms tumors. Subsequent case reports identified the presence of biallelic DICER1 variants as well as progression from cystic nephroma, a benign DICER1-related neoplasm. Despite increasing recognition of ASK as a distinct entity, the optimal treatment remains unclear.

METHODS

Individuals with known or suspected DICER1-related tumors including ASK were enrolled in the International Pleuropulmonary Blastoma/DICER1 Registry. Additionally, a comprehensive review of reported cases of ASK was undertaken, and data were aggregated for analysis with the aim to identify prognostic factors and clinical characteristics to guide decisions regarding genetic testing, treatment, and surveillance.

RESULTS

Ten cases of ASK were identified in the Registry along with 37 previously published cases. Staging data, per Children's Oncology Group guidelines, was available for 40 patients: 13 were stage I, 12 were stage II, 10 were stage III, and five were stage IV. Outcome data were available for 37 patients. Most (38 of 46) patients received upfront chemotherapy and 14 patients received upfront radiation. Two-year event-free survival (EFS) for stage I-II ASK was 81.8% (95% confidence interval [CI]: 67.2%-99.6%), compared with 46.6% EFS (95% CI: 24.7%-87.8%) for stage III-IV (p = .07). Two-year overall survival (OS) for stage I-II ASK was 88.9% (95% CI: 75.5%-100.0%), compared with 70.0% (95% CI: 46.7%-100.0%) for stage III-IV (p = .20). Chemotherapy was associated with improved EFS and OS with hazard ratios of 0.09 (95% CI: 0.02-0.31) and 0.08 (95% CI: 0.02-0.42), respectively.

CONCLUSION

ASK is a rare DICER1-related renal neoplasm. In the current report, we identify clinical and treatment-related factors associated with outcome including the importance of chemotherapy in treating ASK. Ongoing data collection and genomic analysis are indicated to optimize outcomes for children and adults with these rare tumors.

Prognostic role of primary tumor size in Wilms tumor

Wilms tumor (WT) is the most common childhood malignant kidney tumor. The aim of the present study was to determine the impact of primary tumor size on the survival of patients with WT. The data of 1,523 patients diagnosed with WT between 2000 and 2017 were retrieved from the Surveillance, Epidemiology, and End Results database. Receiver operating characteristic curves were plotted to determine the optimal cut-off value of primary tumor size. Overall survival (OS) and cancer-specific survival (CSS) were analyzed using the Kaplan-Meier method and the Cox proportional hazards regression model. The optimal cut-off value for primary tumor size was found to be 11.15 cm. No significant difference in the distribution of tumor size was detected between male and female patients. However, lymph node metastasis and distant metastasis were significantly more frequent in patients whose tumor was ≥11.15 cm in size compared with those with smaller tumors. In addition, patients with larger tumors exhibited significantly worse OS and CSS rates compared with those with smaller tumors. Furthermore, primary tumor size was identified as an independent prognostic factor for OS and CSS in the multivariate analyses. In summary, the present study indicates that primary tumor size is an independent prognostic factor for patients with WT, and tumors ≥11.15 cm are associated with worse OS and CSS.

Treatment of children with favorable histology Wilms tumor with extrapulmonary metastases: A report from the COG studies AREN0533 and AREN03B2 and NWTSG study NWTS-5

BACKGROUND

Patients with stage IV favorable histology Wilms tumor (FHWT) with extrapulmonary metastases (EPM) constitute a small subset of patients with FHWT. Because of their rarity and heterogeneity, optimal FHWT treatment is not well understood. Children's Oncology Group protocol AREN0533 assigned patients with FHWT and EPM to intensified chemotherapy, regimen M, after initial DD-4A chemotherapy. To improve understanding of prognostic factors and best therapies, experiences of patients with EPM on AREN0533, as well as on protocols AREN03B2 and NWTS-5, were reviewed.

METHODS

Combined outcomes for patients with EPM from NWTS-5, AREN0533, and AREN03B2 were determined. Those treated on AREN0533 were compared with those treated on NWTS-5. Prognostic factors were explored in the pooled cohort.

RESULTS

Forty-seven patients with FHWT with EPM enrolled on AREN0533, 37 enrolled on NWTS-5, and 64 were followed only on AREN03B2. The pooled cohort of all 148 patients demonstrated a 4-year event-free survival (EFS) of 77.3% (95% CI, 70.8-84.4) and 4-year overall survival of 88.9% (95% CI, 83.9-94.2). Four-year EFS of patients with EPM treated on AREN0533 was 76.0% (95% CI, 64.6-89.4) vs 64.9% (95% CI, 51.7-82.2) on NWTS-5; hazard ratio, 0.64, p = .26; no difference in overall survival was observed. Increasing linear age and slow incomplete lung response were associated with worse EFS in a pooled cohort.

CONCLUSIONS

Outcomes for patients with EPM are among the lowest for children with FHWT. Further trials with standardized surgical and radiation treatment to metastatic sites, and prospectively collected biologic and treatment details are needed.

CLINICAL TRIAL REGISTRATION

Clinical Trials.gov identifiers: NCT00379340, NCT00898365, and NCT00002611.

Unusual Metastatic Patterns of Wilms Tumor: A Case Series

Wilms tumor (WT) is the most common renal malignancy of childhood. The common metastatic sites are the lungs, liver, and lymph nodes, with brain and bone metastases occurring rarely. Metastatic disease can be present at initial diagnosis or may occur with relapse or disease progression. The majority of relapses in WT occur within the first two years post-treatment. Late relapses are rare. This article describes four cases of WT, each demonstrating an unusual site or timing of metastases. Case 1 presented primarily with jaw metastases, Case 2 presented with bone (vertebrae) and spinal metastases manifesting as paraplegia, at relapse one year after completion of treatment, Case 3 presented with isolated liver metastases four years after treatment completion, and Case 4 presented with brain metastases after six weeks of treatment abandonment. This case series demonstrates the varied pattern of metastases of WT and highlights the need for a high index of suspicion for WT among patients who present with unusual sites of tumor or for metastasis in those who present with neurologic symptoms during or after treatment.

Harmonica consensus, controversies, and future directions in radiotherapy for pediatric Wilms tumors

Radiotherapy (RT) is essential for multimodality treatment of pediatric renal tumors, particularly in higher-risk and metastatic disease. Despite decades of use, particularly for Wilms tumor, there remain controversies regarding RT indications, timing, dose, and targets. To align global management, we address these issues in this international HARMONIsation and CollAboration (HARMONICA) project. There are multiple knowledge gaps and opportunities for future research including: (1) utilization of advanced RT technologies, including intensity-modulated RT, proton beam therapy, combined with image-guided RT to reduce target volumes; (2) impact of molecular biomarkers including loss of heterozygosity at 1p, 16q, and 1q gain on RT indications; (3) mitigation of reproductive toxicity following RT; (4) promotion of RT late effects research; and (5) support to overcome challenges in RT utilization in low- and middle-income countries where 90% of the world's children reside. Here, we outline current status and future directions for RT in pediatric renal tumors.

Challenges in the Management of Wilms Tumor in a Developing Country: A Twenty Years' Experience From a Single Center in Pakistan

BACKGROUND

Wilms Tumor (WT) is one of the most curable childhood cancers. High cure rates seen in the developed countries are not reproduced in developing countries. Lack of access to cancer treatment facilities, financial constraints, late presentation, and abandonment have previously been described. We reviewed our data over the last 20 years to highlight some of these challenges.

METHODS

This is a retrospective chart review of children with WT at our center up to the age of 18 years between 1 November 1997 and 30 November 2017. Demographic details, presentation characteristics and treatment details were recorded. Factors associated with poor outcome were analyzed.

RESULTS

Two hundred eleven children were registered; 117(55.5%) were males. Median age at presentation was 3 (range 0 to 18) years. Presentation data were available for 184/211 patients, staging details for 159/211 and metastatic status for 178/211. Of the available dataset, 60% presented without prior treatment, whereas 40% presented atleast after primary surgical excision. High-stage (stage III or above) disease was present in 79 (49.7%) patients; 61 (34.3%) was presented with metastases or recurrence; 63 (29.8%) abandoned or refused treatment; 99/172 (57.6%) patients finished treatment, 23 (13.4%) died during treatment, and 6 died before treatment. Of the 99 patients who finished treatment 83 (83.8%) are well off therapy; 15(15.2%) relapsed; 6 (40%) are alive after salvage therapy, while 9 (60%) died.

CONCLUSIONS

Our data highlights the challenges of managing WT in resource poor environments. Prior surgery, incomplete staging work-up and abandonment are some of the most frequently encountered barriers. A multipronged approach is required to overcome these challenges.

The necessity of bilateral staging bone marrow examinations for paediatric solid tumours

Background: Bone marrow aspirates and trephine biopsies (BMATs) form an important part of staging to detect bone marrow metastases of both haematological and nonhaematological neoplasms.Aim: The study’s primary aim was to determine whether it is necessary to perform bilateral BMATs on paediatric cancer patients as opposed to unilateral BMATs for the staging of solid tumours.Setting: The Paediatric Oncology Unit at Universitas Academic Hospital (UAH) in Bloemfontein, Free State, South Africa.Methods: A retrospective descriptive study was performed using laboratory reports from 01 January 2015 to 31 December 2019. Data were collected and reported on regarding the total number of staging BMATs performed, the average length of the trephine biopsies, the number of BMATs used for primary diagnosis, the number of bone marrow specimens where metastases were detected (left, right or both), the type of primary cancer and demographic information.Results: One hundred and eighteen patients were included for interpretation. Bone marrow metastases were detected in 28 patients, of which five patients had discrepant left and right results. These five cases included nephroblastoma (n = 2), Hodgkin lymphoma (n = 2) and a germ cell tumour (n = 1).Conclusion: Discrepant results were found in five cases (n = 28; 17.8%). Ultimately, the clinical implication of incorrectly staging solid tumours outweighs the small risks and discomfort of a bilateral bone marrow biopsy.

Outcome of Stage IV Completely Necrotic Wilms Tumour and Local Stage III Treated According to the SIOP 2001 Protocol

Simple Summary

Around 15–20% of all Wilms tumour (WT) patients present with metastatic disease. Approximately 10% of these patients achieve complete necrosis after preoperative chemotherapy, which is associated with a favourable prognosis. The aim of this observational study is to describe the outcome of metastatic patients with completely necrotic (low-risk histology), local stage III WT treated according to the SIOP 2001 protocol, whether or not postoperative radiotherapy was applied.

Abstract

Objective: Wilms tumour (WT) patients with a localised completely necrotic nephroblastoma after preoperative chemotherapy are a favourable outcome group. Since the introduction of the SIOP 2001 protocol, the SIOP– Renal Tumour Study Group (SIOP–RTSG) has omitted radiotherapy for such patients with low-risk, local stage III in an attempt to reduce treatment burden. However, for metastatic patients with local stage III, completely necrotic WT, the recommendations led to ambiguous use. The purpose of this descriptive study is to demonstrate the outcomes of patients with metastatic, completely necrotic and local stage III WT in relation to the application of radiotherapy or not. Methods and materials: all metastatic patients with local stage III, completely necrotic WT after 6 weeks of preoperative chemotherapy who were registered in the SIOP 2001 study were included in this analysis. The pattern of recurrence according to the usage of radiation treatment and 5 year event-free survival (EFS) and overall survival (OS) was analysed. Results: seven hundred and three metastatic WT patients were registered in the SIOP 2001 database. Of them, 47 patients had a completely necrotic, local stage III WT: 45 lung metastases (11 combined localisations), 1 liver/peritoneal, and 1 tumour thrombus in the renal vein and the inferior vena cava with bilateral pulmonary arterial embolism. Abdominal radiotherapy was administered in 29 patients (62%; 29 flank/abdominal irradiation and 9 combined with lung irradiation). Eighteen patients did not receive radiotherapy. Median follow-up was 6.6 years (range 1–151 months). Two of the 47 patients (4%) developed disease recurrence in the lung (one combined with abdominal relapse) and eventually died of the disease. Both patients had received abdominal radiotherapy, one of them combined with lung irradiation. Five-year EFS and OS were 95% and 95%, respectively. Conclusions: the outcome of patients with stage IV, local stage III, completely necrotic Wilms tumours is excellent. Our results suggest that abdominal irradiation in this patient category may not be of added value in first-line treatment, consistent with the current recommendation in the SIOP–RTSG 2016 UMBRELLA protocol.

A nomogram for prediction of distant metastasis in children with wilms tumor: A study based on SEER database

INTRODUCTION

Accurate diagnosis of distant metastasis especially uncommon site of metastasis (UCM) in patients with Wilms tumor (WTs) is a demanding prerequisite for administration of appropriate therapy and achieving better survival outcome.

OBJECTIVE

To develop and validate a nomogram to predict probability of distant metastasis, and identify population demanded for rigorous imaging evaluations in children with WTs.

MATERIAL AND METHODS

Data of patients diagnosed with unilateral WTs and aged under 18 years old, were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. The included patients were randomly allocated to the training and the validation cohort. Logistic regression analyses were performed to identify the independent risk factors and develop a predicting model of distant metastasis in WTs. The model-based nomogram was created and internally validated. Cut-off value of nomogram points was derived by using the receiver operating characteristics (ROC) curve analysis. Performance of the nomogram was evaluated in terms of discrimination, calibration and clinical usefulness.

RESULTS

A total 717 WTs patients were included in the study. Age at diagnosis (OR 1.173, 95%CI: 1.079-1.279), LND (OR 8.260, 95%CI: 2.837-24.814) and tumor size (OR 2.141, 95%CI: 1.378-3.329) were identified as the independent risk factors of distant metastasis in WTs. These three factors were incorporated to develop a model and a nomogram. The nomogram presented with good discriminative ability in the training cohort (C-statistics, 0.703) and validation cohort (C-statistics, 0.764), respectively. The calibration curves demonstrated adequate agreement between predicted probability and observed probability of distant metastasis. The nomogram also revealed its clinical usefulness by application of decision curve analysis (DCA). Cut-off value of nomogram points was 58 and its corresponding probability of distant metastasis was 0.22. The value was applied in risk stratification dividing the general cohort into high-risk and low-risk group.

DISCUSSION

Our study for the first time developed and validated a model and a visualized nomogram for individualized prediction of distant metastasis in WTs. C-statistics, calibration curves and DCA demonstrated good performance and clinical usefulness of the nomogram. Patients stratified as high-risk group were demanded for rigorous imaging evaluations to accurately identify UCM.

CONCLUSION

The nomogram, developed by incorporation of three independent risk factors, which are age at diagnosis, LND and tumor size, is used to facilitate individualized prediction of distant metastasis in WTs. Rigorous imaging evaluations are recommended for patients in high-risk group to identify UCM.

Predictors of treatment outcome of Wilms Tumour in low-income country; single centre experience from Pakistan

BACKGROUND

Wilms tumor (WT) represents around 85% of pediatric renal tumors. In high-income countries, 5-years survival of WT is above 90% but survival in developing countries is inferior.

OBJECTIVE

To identify the predictors of treatment outcome of WT in a developing country.

METHODS

A retrospective study conducted at the pediatric oncology department, Combined Military Hospital Rawalpindi, Pakistan. All newly diagnosed WT cases from 1st January 2012 who completed their treatment before 31st August 2019 were evaluated. Treatment was based on SIOP Wilms Tumour 2001/UK version 5. Patients presenting before nephrectomy received pre-operative chemotherapy. The postoperative chemotherapy regimen was decided according to the stage, risk stratification and metastatic status of the patient.

RESULTS

Data of 84 cases, including 40 (47.6%) males and 44 (52.4%) females was analyzed. The mean diagnostic age was 38.87 ± 28.66 months and 68 (81%) cases were less than five years of age. The commonest presenting features were abdominal mass in 75 (89.3%) cases. The right kidney was affected in 43 (51.2%) cases. Stage I disease was documented in 27 (32.1%) cases, stage II in 25 (29.8%), stage III in 13 (15.5%), and stage IV in 17 (20.2%) cases. In univariate analysis, advanced stage (P = < 0.001) and metastatic disease (P=< 0.001) adversely affected the treatment outcome. Multivariate analysis demonstrated that advanced stage WT was associated with the worst outcome (P= < 0.05). Four (4.8%) cases had treatment-related mortality (TRM). With a median follow-up time of 28.26 ± 23.03 months, OS and EFS were 66 (78.6%) and 63 (75.0%) respectively.

DISCUSSION

Delayed presentation with advanced-stage metastatic disease is quite common in the developing courtiers and is the major contributor to decreased EFS and OS. In the present study, 20.2% cases had metastatic disease, which is similar to reported from other developing countries. OS decreased from 92.6% in stage I to 47.1% in stage IV disease (P=< 0.001) and EFS decreased from 92.6% in stage I to 43.8% in stage IV disease (P=< 0.001). Very similar results are reported by a regional study [17]. Results in stage I and II disease are comparable to documented in the western world and inferior in advanced-stage disease. The strength of the present study is that multiple factors, affecting the treatment outcome of WT over almost seven years period were evaluated.

CONCLUSIONS

Stage of the disease is the most important prognostic factor. Delayed presentation with metastatic disease has a poor outcome.