Current treatment for Wilms tumor: COG and SIOP standards

A comprehensive overview of liquid biopsy applications in pediatric solid tumors

Liquid biopsies are emerging as an alternative source for pediatric cancer biomarkers with potential applications during all stages of patient care, from diagnosis to long-term follow-up. While developments within this field are reported, these mainly focus on dedicated items such as a specific liquid biopsy matrix, analyte, and/or single tumor type. To the best of our knowledge, a comprehensive overview is lacking. Here, we review the current state of liquid biopsy research for the most common non-central nervous system pediatric solid tumors. These include neuroblastoma, renal tumors, germ cell tumors, osteosarcoma, Ewing sarcoma, rhabdomyosarcoma and other soft tissue sarcomas, and liver tumors. Within this selection, we discuss the most important or recent studies involving liquid biopsy-based biomarkers, anticipated clinical applications, and the current challenges for success. Furthermore, we provide an overview of liquid biopsy-based biomarker publication output for each tumor type based on a comprehensive literature search between 1989 and 2023. Per study identified, we list the relevant liquid biopsy-based biomarkers, matrices (e.g., peripheral blood, bone marrow, or cerebrospinal fluid), analytes (e.g., circulating cell-free and tumor DNA, microRNAs, and circulating tumor cells), methods (e.g., digital droplet PCR and next-generation sequencing), the involved pediatric patient cohort, and proposed applications. As such, we identified 344 unique publications. Taken together, while the liquid biopsy field in pediatric oncology is still behind adult oncology, potentially relevant publications have increased over the last decade. Importantly, steps towards clinical implementation are rapidly gaining ground, notably through validation of liquid biopsy-based biomarkers in pediatric clinical trials.

Wilms Tumor with Vena Caval Intravascular Extension: A Surgical Perspective

Wilms tumor (WT) is the most common kidney tumor in pediatric patients. Intravascular extension of WT above the level of the renal veins is a rare manifestation that complicates surgical management. Patients with intravascular extension are frequently asymptomatic at diagnosis, and tumor thrombus extension is usually diagnosed by imaging. Neoadjuvant chemotherapy is indicated for thrombus extension above the level of the hepatic veins and often leads to thrombus regression, obviating the need for cardiopulmonary bypass in cases of cardiac thrombus at diagnosis. In cases of tumor extension to the retrohepatic cava, neoadjuvant therapy is not strictly indicated, but it may facilitate the regression of tumor thrombi, making resection safer. Hepatic vascular isolation and cardiopulmonary bypass increase the risk of bleeding and other complications when utilized for tumor thrombectomy. Fortunately, WT patients with vena caval with or with intracardiac extension have similar overall and event-free survival when compared to patients with WT without intravascular extension when thrombectomy is successfully performed. Still, patients with metastatic disease at presentation or unfavorable histology suffer relatively poor outcomes. Dedicated pediatric surgical oncology and pediatric cardiothoracic surgery teams, in conjunction with multimodal therapy directed by a multidisciplinary team, are preferred for optimized outcomes in this patient population.

Staging and Restaging Pediatric Abdominal and Pelvic Tumors: A Practical Guide

The most common abdominal malignancies diagnosed in the pediatric population include neuroblastoma, Wilms tumor, hepatoblastoma, lymphoma, germ cell tumor, and rhabdomyosarcoma. There are distinctive imaging findings and patterns of spread for each of these tumors that radiologists must know for diagnosis and staging and for monitoring the patient's response to treatment. The multidisciplinary treatment group that includes oncologists, surgeons, and radiation oncologists relies heavily on imaging evaluation to identify the best treatment course and prognostication of imaging findings, such as the image-defined risk factors for neuroblastomas, the PRETreatment EXtent of Disease staging system for hepatoblastoma, and the Ann Arbor staging system for lymphomas. It is imperative for radiologists to be able to correctly indicate the best imaging methods for diagnosis, staging, and restaging of each of these most prevalent tumors to avoid inconclusive or unnecessary examinations. The authors review in a practical manner the most updated key points in diagnosing and staging disease and assessing response to treatment of the most common pediatric abdominal tumors. ©RSNA, 2024 Supplemental material is available for this article.

Case Report: Autosomal dominant polycystic kidney disease and Wilms' tumor in infancy and childhood

Background

Autosomal dominant polycystic kidney disease (ADPKD) is rare but one of the most common inherited kidney diseases. Normal kidney function is maintained until adulthood in most patients. About 7 in 10 patients with ADPKD develop kidney failure in the latter half of their fifth decade of life. Wilms' tumor, or nephroblastoma, is the most common malignant tumor stemming from kidney cells in the pediatric age group. This type of tumor is the most frequently occurring kidney malignancy in children between the ages of 0 and 5 years. The exact cause of Wilms' tumor is unknown, though about 10% of cases have a genetic predisposition. Wilms' tumor is one of the most successfully treated childhood oncological diseases. Overall, the 5-year survival rates were approximately 90% in both the National Wilms Tumor Study (NWTS) and Paediatric Oncology SIOP studies, showing similar results.

Case presentation

We report a case of a girl diagnosed with autosomal polycystic kidney disease, who subsequently developed Wilms' tumor and underwent successful treatment with chemotherapy. Polycystic kidney disease was suspected in the fetus during prenatal ultrasound and confirmed after birth with ultrasound and genetic testing. The Wilms tumor was an accidental finding during abdominal MRI at the age of 2 years old to rule out liver pathology.

Conclusion

Reports on whether a diagnosis of ADPKD is a risk factor for malignancy are conflicting. In this particular case, Wilms' tumor is present in the background of polycystic kidney disease and was timely diagnosed by an incidental MRI.

Grossing to reporting of Wilms tumor with emphasis on proper sampling in treatment-naive and postchemotherapy specimens and their clinicopathological correlation with outcome

Context

Emphasis on grossing to reporting for the assessment of histopathological parameters predicting outcomes in Wilms tumor.

Aims

To analyze various clinicopathological parameters that effect outcomes in treatment naïve and post chemotherapy Wilms tumor specimens.

Settings and Design

This was a retrospective observational study.

Subjects and Methods

All patients diagnosed with Wilms tumor between 2012 and 2018 at our institute will be included with their clinical findings, laboratory reports, and radiological findings. The patients will be categorized into two groups based on treatment protocol (Society of Pediatric Oncology (SIOP) or the National Wilms Tumor Study Group/Children's Oncology Group (COG) guidelines) used. Details of Grossing and reporting protocols used for the in pre treatment and post treatment specimens will be analyzed. Follow-up till December 2020 will be analyzed.

Statistical Analysis Used

Chi-square and Fisher's exact tests were used for statistical analysis.

Results

A total of 36 patients with the diagnosis of Wilms tumor were included in the present study. The mean age of presentation was 3.9 ± 0.7 years, and males were more common than females. Most of them presented as abdominal mass and few with isolated hematuria. Twenty-six (72%) patients were treated under SIOP protocol with preoperative neoadjuvant chemotherapy. Ten patients underwent upfront surgery as per COG protocol. In SIOP group patients, the mean tumor size was 9.3cm. Forty percent (n = 10) we mixed histological type followed by blastemal type constituting (32%, n = 8). Regressive and epithelial histological types constituted 16% (n = 4) and 12% (n = 3), respectively. In the SIOP group 72% (n = 19) had no anaplasia and 28% (n = 7) had anaplasia. Fifty seven percent (n = 15) cases were Stage I, followed by 26.9% n = 7) and 11.5% (n = 3) being Stage II and Stage III, respectively. Ten patients underwent upfront surgery as per COG protocol. The mean tumor size among this group was 8 cm ranging from 7 cm to 11 cm. Eight (80%) cases had favorable histology and two cases showed focal anaplasia. Heterologous differentiation is seen in 3 (70%). Out of the 10 cases, one case was Stage I, six were Stage 2, one was Stage III, and two were clinical Stage IV. None of the cases showed either vessel or lymph node metastasis. All the patients received adjuvant chemotherapy postsurgery and were followed up till December 2020 for (at least 3 years). Of 25 patients in the SIOP group, 18 (72%) had complete remission with no radiological evidence of residual disease. Of the 10 patients in the COG group, 6 (70%) had complete remission.

Conclusions

Histopathological evaluation of Wilms tumor is a critical aspect in the management of Wilms tumor, as tumor characteristics are different in the tumors treated under SIOP and COG protocols, which will ultimately affect the prognostic risk stratification. This necessitates the knowledge of the important grossing and reporting of these tumors under the two protocols.

Prechemotherapy Transperitoneal Robotic-Assisted Partial Nephrectomy (RAPN) for a Wilms Tumor: Surgical and Oncological Outcomes in a Four-Year-Old Patient

BACKGROUND

Wilms tumor (WT) is the most frequent renal tumor in children. The SIOP-UMBRELLA Guidelines allow for nephron-sparing surgery (NSS) in syndromic patients, as well as in cases of small (<300 mL) non-syndromic unilateral WTs, without lymph node involvement, and with a substantial expected remnant renal function, following neoadjuvant chemotherapy. We present a case of prechemotherapy transperitoneal robot-assisted partial nephrectomy (RAPN) for a unilateral, non-syndromic Wilms tumor.

METHODS

A four-year-old child presented with a solid mass measuring 3.6 cm in diameter involving the upper right renal pole, incidentally detected during an abdominal echotomography. CT scan and abdominal MRI revealed no local infiltration or lymph node involvement, suggesting that the exophytic mass could be easily resected via an NSS robotic approach. Preoperative imaging did not strongly suggest WT. A virtual 3D reconstruction of the tumor was performed.

RESULTS

After the oncologic board approval, a robot-assisted partial nephrectomy with an intraperitoneal approach was performed. Histopathological analysis confirmed the diagnosis of WT. The patient subsequently received 10 doses of vincristine as adjuvant chemotherapy. A 28-month follow-up showed no tumor recurrence.

CONCLUSIONS

Intraperitoneal RAPN may be an option for selected WT and warrants consideration as a challenging but advantageous approach.

Automated Deep Learning-Based Classification of Wilms Tumor Histopathology

(1) Background: Histopathological assessment of Wilms tumors (WT) is crucial for risk group classification to guide postoperative stratification in chemotherapy pre-treated WT cases. However, due to the heterogeneous nature of the tumor, significant interobserver variation between pathologists in WT diagnosis has been observed, potentially leading to misclassification and suboptimal treatment. We investigated whether artificial intelligence (AI) can contribute to accurate and reproducible histopathological assessment of WT through recognition of individual histopathological tumor components. (2) Methods: We assessed the performance of a deep learning-based AI system in quantifying WT components in hematoxylin and eosin-stained slides by calculating the Sørensen-Dice coefficient for fifteen predefined renal tissue components, including six tumor-related components. We trained the AI system using multiclass annotations from 72 whole-slide images of patients diagnosed with WT. (3) Results: The overall Dice coefficient for all fifteen tissue components was 0.85 and for the six tumor-related components was 0.79. Tumor segmentation worked best to reliably identify necrosis (Dice coefficient 0.98) and blastema (Dice coefficient 0.82). (4) Conclusions: Accurate histopathological classification of WT may be feasible using a digital pathology-based AI system in a national cohort of WT patients.

Identification and Characterization of the Wilms Tumor Cancer Stem Cell

A nephrogenic progenitor cell (NP) with cancer stem cell characteristics driving Wilms tumor (WT) using spatial transcriptomics, bulk and single cell RNA sequencing, and complementary in vitro and transplantation experiments is identified and characterized. NP from WT samples with NP from the developing human kidney is compared. Cells expressing SIX2 and CITED1 fulfill cancer stem cell criteria by reliably recapitulating WT in transplantation studies. It is shown that self-renewal versus differentiation in SIX2+CITED1+ cells is regulated by the interplay between integrins ITGβ1 and ITGβ4. The spatial transcriptomic analysis defines gene expression maps of SIX2+CITED1+ cells in WT samples and identifies the interactive gene networks involved in WT development. These studies define SIX2+CITED1+ cells as the nephrogenic-like cancer stem cells of WT and points to the renal developmental transcriptome changes as a possible driver in regulating WT formation and progression.

Wilms tumor in children: A multivariate analysis of prognostic factors, with emphasis on inferior vena cava/right atrium extension. Results from a single-center study

BACKGROUND

To identify prognostic factors for overall survival through the analysis of 132 patients with Wilms tumor followed at a single center, with emphasis on the inferior vena cava/right atrium extension.

METHODS

Retrospective analysis of overall survival using logistic regression models and including age, sex, clinical features, associated syndromes, comorbidities, tumor size before chemotherapy, stage, presence of metastatic disease and its site, invasion of adjacent structures, inferior vena cava/right atrium extension, laterality, tumor histology, chemotherapy protocol, and radiotherapy as potential risk factors.

RESULTS

From January 2000 through November 2021, 132 patients met the inclusion criteria, 64 females and 68 males; 15 (11.4%) patients presented with tumoral extension to inferior vena cava/right atrium and 44 had metastatic disease (33.3%). Based on logistic regression, the factors correlating to a fatal outcome were male sex (p = 0.046), high risk histology (p = 0.036), and the presence of metastatic disease (p = 0.003). None of the patients presenting inferior vena cava/right atrium extension died (p = 0.992). In a specific analysis of metastatic sites, hepatic metastasis alone showed correlation with a fatal outcome (p = 0.001).

CONCLUSION

These results underline the importance of identifying and treating metastatic disease and high-risk tumors. The female gender as a potential driver for a less aggressive disease is a new finding that deserves further investigation. The accurate identification of inferior vena cava/right atrium extension, subsequent preoperative chemotherapy, and resection with a skilled team promoted survival rates of all patients.

LEVEL OF EVIDENCE

II.

Meta-Analysis on Long-Term Outcomes of Pediatric Renal Cancer Survivors Following COG and SIOP Protocols

BACKGROUND

 Pediatric renal cancer survivors have higher rate of chronic renal disease and hypertension. These patients have similar survival rates when treated according to either Children's Oncology Group (COG) or International Society of Pediatric Oncology (SIOP) protocols. We aimed to compare the late outcome of these two approaches.

METHODS

 We performed a meta-analysis of all studies from 2000 to 2021; database search using keywords: long-term outcomes OR late effects, nephrectomy, pediatric renal cancer. For each protocol, data were collected, and the "pooled" outcomes were compared. Continuous and dichotomous variables were obtained with a 95% odds ratio.

RESULTS

 Sixteen studies with a total of 715 pediatric renal cancer survivors were analyzed. The mean follow-up time was 17.4 (standard deviation 5.6) years. Reduced renal function and hypertension were the most encountered long-term complications. The mean estimated glomerular filtration rate was similar in both protocols (101.62 vs. 101.70 mL/min/1.73 m²), while the prevalence of hypertension was 23% in COG and 10% in SIOP. The prevalence of secondary malignancy was 1.1% in COG and 6.7% in SIOP (1.1% vs. 6.7%, p ≤ 0.001). Chronic kidney disease was similar in both groups.

CONCLUSION

 A high prevalence of hypertension was observed among pediatric renal cancer survivors, as well as an increased risk of a secondary tumor. These results emphasize the importance of long-term follow-up into adulthood, to promptly diagnose any long-term side effects of the treatment. Thanks to the increased overall survival, future protocols will pay attention to the reduction of long-term sequelae.

Unusual Renal Mass in a Pediatric Patient

Renal cell carcinoma (RCC) is rare in the pediatric population, comprising about 5% of renal neoplasms in children.¹ Out of all childhood cases of RCC, translocation RCCs (tRCC) is the most common.² It is well described in the literature that exposure to alkylating agents such as cyclophosphamide and/or topoisomerase II inhibitors such as doxorubicin and etoposide, is a risk factor for the development of Xp11 (or TFE3) tRCC.³ Herein is a case of tRCC development in a patient with history of exposure to topoisomerase II inhibitors and alkylating agents to treat a common childhood malignancy.

Preoperative radiomic signature based on CT images for noninvasive evaluation of localized nephroblastoma in pediatric patients

Background

Nephron sparing nephrectomy may not reduce the prognosis of nephroblastoma in the absence of involvement of the renal capsule, sinus vessels, and lymph nodes, However, there is no accurate preoperative noninvasive evaluation method at present.

Materials and methods

105 nephroblastoma patients underwent contrast-enhanced CT scan between 2013 and 2020 in our hospital were retrospectively collected, including 59 cases with localized stage and 46 cases with non-localized stage, and then were divided into training cohort (n= 73) and validation cohort (n= 32) according to the order of CT scanning time. After lesion segmentation and data preprocessing, radiomic features were extracted from each volume of interest. The multi-step procedure including Pearson correlation analysis and sequential forward floating selection was performed to produce radiomic signature. Prediction model was constructed using the radiomic signature and Logistic Regression classifier for predicting the localized nephroblastoma in the training cohort. Finally, the model performance was validated in the validation cohort.

Results

A total of 1652 radiomic features have been extracted, from which TOP 10 features were selected as the radiomic signature. The area under the receiver operating characteristic curve, accuracy, sensitivity and specificity of the prediction model were 0.796, 0.795, 0.732 and 0.875 for the training cohort respectively, and 0.710, 0.719, 0.611 and 0.857 for the validation cohort respectively. The result comparison with prediction models composed of different machine learning classifiers and different parameters also manifest the effectiveness of our radiomic model.

Conclusion

A logistic regression model based on radiomic features extracted from preoperative CT images had good ability to noninvasively predict nephroblastoma without renal capsule, sinus vessel, and lymph node involvement.

Targeted treatment of solid tumors in pediatric precision oncology

The treatment of childhood solid cancer has markedly evolved in recent years following a refined molecular characterization and the introduction of novel targeted drugs. On one hand, larger sequencing studies have revealed a spectrum of mutations in pediatric tumors different from adults. On the other hand, specific mutations or immune dysregulated pathways have been targeted in preclinical and clinical studies, with heterogeneous results. Of note, the development of national platforms for tumor molecular profiling and, in less measure, for targeted treatment, has been essential in the process. However, many of the available molecules have been tested only in relapsed or refractory patients, and have proven poorly effective, at least in monotherapy. Our future approaches should certainly aim at improving the access to molecular characterization, to obtain a deeper picture of the distinctive phenotype of childhood cancer. In parallel, the implementation of access to novel drugs should not only be limited to basket or umbrella studies but also to larger, multi-drug international studies. In this paper we reviewed the molecular features and the main available therapeutic options in pediatric solid cancer, focusing on available targeted drugs and ongoing investigations, aiming at providing a useful tool to navigate the heterogeneity of this promising but complex field.

Etiologies, Gross Appearance, Histopathological Patterns, Prognosis, and Best Treatments for Subtypes of Renal Carcinoma: An Educational Review

Of all primary renal neoplasms, 80-85% are renal cell carcinomas (RCCs), which develop in the renal cortex. There are more than 10 histological and molecular subtypes of the disease, the most frequent of which is clear cell RCC, which also causes most cancer-related deaths. Other renal neoplasms, including urothelial carcinoma, Wilms' tumor, and renal sarcoma, each affect a particular age group and have specific gross and histological features. Due to the genetic susceptibility of each of these malignancies, early mutation discovery is necessary for the early detection of a tumor. Furthermore, it is crucial to avoid environmental factors leading to each type. This study provides relatively detailed and essential information regarding each subtype of renal carcinoma.

Embolization in Pediatric Patients: A Comprehensive Review of Indications, Procedures, and Clinical Outcomes

Embolization in pediatric patients encompasses a large spectrum of indications, ranging from the elective treatment of congenital diseases of the cardiovascular system to the urgent management of acute hemorrhagic conditions. In particular, the endovascular treatment of central and peripheral vascular malformations and hypervascular tumors represents a wide chapter for both congenital and acquired situations. Thanks to the progressive availability of low-profile endovascular devices and new embolic materials, the mini-invasive approach has gradually overtaken surgery. In this review, the main embolization procedures will be illustrated and discussed, with a focus on clinical indications and expected outcomes. The most recent mini-invasive techniques will be described, with hints on the cutting-edge devices and embolic materials.

Breast Cancer Secondary to Radiation Therapy in a Patient With Wilms Tumor

Wilms tumor, one of the most common childhood malignancies, is typically treated with a combination of chemotherapy, radiation, and surgical resection. Wilms tumor survivors who received radiation therapy are, however, at a higher risk of secondary malignancies and need vigilant monitoring. We present the case of a 35-year-old female with history of Wilms tumor at age five, who received radiation therapy for pulmonary metastasis, and was found to have breast cancer at the age of 35. We discuss different protocols in treatment of Wilms tumor and current secondary malignancy screening recommendations. We also recognize the importance of screening guideline awareness among primary care physicians and its mortality and morbidity implications.

The role of liver resection in metastatic nephroblastoma: a systematic review and Meta-regression analysis

BACKGROUND

The impact of hepatic resection for liver metastases (LM) on the survival of pediatric patients with Wilms' tumor (WT) is unclear. So far, there is a lack of studies investigating the best suited treatment for patients with WTLM, and the role of liver resection has rarely been investigated. Thus, the development of evidence-based guidelines concerning indications of liver resection for WTLM remains difficult.

AIM

To investigate the role of surgery in the therapy of WTLM. All available data on liver resections and subgroup outcomes of patients with WTLM are analyzed. Main research question is whether liver resection improves survival rates of patients with WTLM compared to non-surgical treatment.

METHODS

A systematic literature search of MEDLINE, Web of Science, and Central provided the basis for this PRISMA-compliant systematic review. For the main analysis (I), all studies reporting on surgical treatment of pediatric WTLM were included. To provide a representative overview of the general outcome of WTLM patients, in analysis II all studies with cohorts of at least five WTLM patients, regardless of the kind of treatment, were reviewed and analyzed. A Multiple meta-regression model was applied to investigate the impact liver resection on overall survival.

RESULTS

14 studies with reports of liver resection for WTLM were found (Analysis I). They included a total of 212 patients with WTLM, of which 93 underwent a liver resection. Most studies had a high risk of bias, and the quality was heterogenous. For the analysis II, eight studies with subgroups of at least five WTLM patients were found. The weighted mean overall survival (OS) of WTLM patients across the studies was 55% (SD 29). A higher rate of liver resection was a significant predictor of better OS in a multiple meta-regression model with 4 covariates (I2 29.43, coefficient 0.819, p = 0.038).

CONCLUSIONS

This is the first systematic review on WTLM. Given a lack of suited studies that specifically investigated WTLM, ecological bias was high in our analyses. Generating evidence is complicated in rare pediatric conditions and this study must be viewed in this context. Meta-regression analyses suggest that liver resection may improve survival of patients with WTLM compared to non-surgical treatment. Especially patients with persisting disease after neoadjuvant chemotherapy but also patients with metachronous LM seem to benefit from resection. Complete resection of LM is vital to achieve higher OS. Studies that prospectively investigate the impact of surgery on survival compared to non-surgical treatment for WTLM are highly needed to further close the current evidence gap.

STUDY REGISTRATION

PROSPERO 2021 CRD42021249763  https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=249763 .

Machine Learning-Based CT Radiomics Method for Identifying the Stage of Wilms Tumor in Children

PURPOSE

To develop and validate a machine learning-based CT radiomics method for preoperatively predicting the stages (stage I and non-stage I) of Wilms tumor (WT) in pediatric patients.

METHODS

A total of 118 patients with WT, who underwent contrast-enhanced computed tomography (CT) scans in our center between 2014 and 2021, were studied retrospectively and divided into two groups: stage I and non-stage I disease. Patients were randomly divided into training cohorts (n = 94) and test cohorts (n = 24). A total of 1,781 radiomic features from seven feature classes were extracted from preoperative portal venous-phase images of abdominal CT. Synthetic Minority Over-Sampling Technique (SMOTE) was used to handle imbalanced datasets, followed by a t-test and Least Absolute Shrinkage and Selection Operator (LASSO) regularization for feature selection. Support Vector Machine (SVM) was deployed using the selected informative features to develop the predicting model. The performance of the model was evaluated according to its accuracy, sensitivity, and specificity. The receiver operating characteristic curve (ROC) and the area under the ROC curve (AUC) was also arranged to assess the model performance.

RESULTS

The SVM model was fitted with 15 radiomic features obtained by t-test and LASSO concerning WT staging in the training dataset and demonstrated favorable performance in the testing dataset. Cross-validated AUC on the training dataset was 0.79 with a 95 percent confidence interval (CI) of 0.773-0.815 and a coefficient of variation of 3.76%, while AUC on the test dataset was 0.81, and accuracy, sensitivity, and specificity were 0.79, 0.87, and 0.69, respectively.

CONCLUSIONS

The machine learning model of SVM based on radiomic features extracted from CT images accurately predicted WT stage I and non-stage I disease in pediatric patients preoperatively, which provided a rapid and non-invasive way for investigation of WT stages.

Diagnostic accuracy and cytomorphological spectrum of Wilms tumour in fine needle aspiration biopsy cytology samples supplemented with cell blocks

OBJECTIVE

Paediatric malignant renal neoplasms are subjected to neoadjuvant chemotherapy as per Societe Internationale d'Oncologie Pediatrique; International Society of Pediatric Oncology (SIOP) protocol. An accurate tissue diagnosis is required prior to institution of chemotherapy, and hence the aim of this study was to evaluate the diagnostic accuracy of fine needle aspiration biopsy cytology (FNABC) along with cell block histology.

MATERIALS AND METHODS

A retrospective audit of all paediatric renal neoplasms diagnosed by FNABC between 2015 and 2019 was performed. Histopathology correlation was done wherever available. WT cases were subjected to detailed cytomorphological evaluation.

RESULTS

A total of 121 cases of paediatric renal neoplasms including 109 WT, four clear cell sarcoma, one malignant rhabdoid tumour and three mesoblastic nephroma were evaluated. The age range was 4 weeks to 8 years. FNABC samples were adequate for diagnosis in 120 of 121 cases (99.18%) and a definitive cytological diagnosis was achieved in 117 cases (96.7%). The specificity and sensitivity for a cytopathological diagnosis of WT were 98.7% and 97.4%, respectively. On detailed cytomorphological analysis of 68 histopathology-proven WT, 40 (58.8%) cases were triphasic, 23 (35.3%) were biphasic and four were composed of blastema only. The corresponding cell blocks provided additional information over the conventional smears in 23 (33.8%) cases, with epithelial or mesenchymal elements recognised and evidence of rhabdomyoblastic differentiation.

CONCLUSION

FNABC along with cell block histology is highly accurate for diagnosis of WT and other malignant paediatric renal neoplasms and is recommended as the technique of choice in centres with cytopathology expertise for establishing a cellular diagnosis prior to commencement of neoadjuvant chemotherapy.

Adult Wilms' Tumor: Case Report and Literature Review

Wilms' tumor is childhood’s most common renal tumor, and its presentation in the adult age is extremely rare. Due to the low frequency in adults, no standard management guidelines are available for this population, also the natural history of the disease and management is unclear. We present a case report of a 31-year-old woman with metastatic Wilms' tumor, with lymph node, lung and liver involvement; systemic treatment with chemotherapy was started, with complete clinical response. Finally, a literature review is performed to showcase the differences in the clinical course, prognosis, and treatment alternatives, in adult disease compared to childhood.

Non-coding RNAs in Wilms' tumor: biological function, mechanism, and clinical implications

Non-coding RNAs are involved with maintenance and regulation of physiological mechanisms and are involved in pathological processes, such as cancer. Among the small ncRNAs, miRNAs are the most explored in tumorigenesis, metastasis development, and resistance to chemotherapy. These small molecules of ~ 22 nucleotides are modulated during early renal development, involved in the regulation of gene expression and Wilms' tumor progression. Wilms' tumors are embryonic tumors with few mutations and complex epigenetic dysregulation. In recent years, the small ncRNAs have been explored as potentially related both in physiological development and in the tumorigenesis of several types of cancer. Besides, genes regulated by miRNAs are related to biological pathways as PI3K, Wnt, TGF-β, and Hippo signaling pathways, among others, which may be involved with the underlying mechanisms of resistance to chemotherapy, and in this way, it has emerged as potential targets for cancer therapies, including for Wilms' tumors.

Many faces of Wilms Tumor: Recent advances and future directions

Background

Wilms’ tumor (WT) is the most frequently occurring paediatric renal tumor and is one of the most treatment-responsive tumors. A tumor-suppressor gene and other genetic abnormalities have been implicated in its etiology. In addition, patients with many congenital anomalies, such as Beckwith-Wiedemann syndrome, WAGR syndrome and Denys-Drash syndrome, have an increased risk of WT.

Methods and results

Two large collaborative groups – National Wilms Tumor Study Group (NWTSG)/Children's Oncology Group (COG) and The International Society of Paediatric Oncology (SIOP) have laid down the guidelines for standardized treatment of WT, though differing in the diagnostic and therapeutic approach. The major difference in the two guidelines is the timing of surgery: SIOP recommends using preoperative chemotherapy and NWTSG/COG prefers primary surgery before any adjuvant treatments. Both these groups currently aim at intensifying treatment for patients with poor prognosticators while appropriating the therapy to reduce long-term complications for those with favourable prognostic features. As the survival rate has now reached 90%, the primary objectives of the physician are to perform nephron-sparing surgery in selected cases and to reduce the dosage and duration of chemotherapy and radiotherapy in appropriate cases. The purpose of this review is to present current standards of diagnosis and treatment of WT around the world.

Conclusion

Further studies in future should be done to highlight the use of chemotherapy and radiotherapy under risk-stratified strategies. Further improvement in survival of these children can only be achieved by increasing awareness, early recognition, appropriate referral, and a multidisciplinary approach.

•

o Most of the patients with WT have good prognosis.

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o Multimodality treatment and multidisciplinary care are the major contributors for an improved prognosis.

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o Further studies should be done on usage of chemotherapy and radiotherapy under more accurate risk-stratified strategies and to decrease the late effects of surgery.

[Clinical effect of multicenter multidisciplinary treatment in children with renal malignant tumors]

OBJECTIVE

To study the long-term clinical effect of multicenter multidisciplinary treatment (MDT) in children with renal malignant tumors.

METHODS

A retrospective analysis was performed on the medical data of 55 children with renal malignant tumors who were diagnosed and treated with MDT in 3 hospitals in Hunan Province from January 2015 to January 2020, with GD-WT-2010 and CCCG-WT-2016 for treatment regimens. A Kaplan-Meier survival analysis was used to analyze the survival of the children.

RESULTS

Of the 55 children, 10 had stage I tumor, 14 had stage Ⅱ tumor, 22 had stage Ⅲ tumor, 7 had stage IV tumor, and 2 had stage V tumor. As for pathological type, 47 had FH type and 8 had UFH type. All children underwent complete tumor resection. Of the 55 children, 14 (25%) received preoperative chemotherapy. All children, except 1 child with renal cell carcinoma, received postoperative chemotherapy. Among the 31 children with indication for radiotherapy, 21 (68%) received postoperative radiotherapy. One child died of postoperative metastasis. The incidence rate of FH-type myelosuppression was 94.4%, and the incidence rate of UFH-type myelosuppression was 100%. The median follow-up time was 21 months and the median survival time was 26 months for all children, with an overall survival rate of 98% and an event-free survival rate of 95%.

CONCLUSIONS

Multicenter MDT has the advantages of high success rate of operation and good therapeutic effect of chemotherapy in the treatment of children with renal malignant tumors, with myelosuppression as the most common side effects, and radiotherapy is safe and effective with few adverse events. Therefore, MDT has good feasibility, safety, and economy.