Management and outcome of pediatric Wilms tumor with malignant inferior Vena cava thrombus: largest cohort of single-center experience

BACKGROUND

Wilms tumor (WT) with an inferior Vena cava (IVC) malignant thrombus comprises 4-10% of all WT cases.

METHODS

This retrospective analysis included 51 pediatric patients presenting at Children Cancer Hospital Egypt-57357 from July 2007 to December 2016 with the diagnosis of WT with malignant IVC thrombus.

RESULTS

Median age at presentation = 4.4 years and 28 cases (55%) were females. Twenty-five patients (49%) were metastatic and 4 patients (7.8%) had bilateral disease. Forty-seven cases (92.2%) had favorable histology with no evidence of anaplasia. Level of thrombus extension at presentation was classified as infra-hepatic, retro-hepatic, supra-hepatic and intra-cardiac in 33, 9, 6 and 3 patients, respectively. Fifty patients started neoadjuvant chemotherapy (CTH) with 16 patients showing complete resolution of thrombus after 6 weeks of CTH. None of the patients developed thrombus progression after neoadjuvant CTH; one patient had stationary intra-cardiac thrombus, while remaining patients showed partial regression of their thrombus and had nephrectomy with en-bloc thrombectomy. The mean cranio-caudal dimension of IVC thrombi at initial presentation was 6.5 cm, and 3.6 cm post 6th week of CTH. The 5-year OS and EFS were 75.9% and 71.1%, respectively. There was no significant correlation of initial levels of thrombus extension with survival.

CONCLUSION

Neoadjuvant chemotherapy followed by radical nephrectomy with en-bloc thrombectomy and radiotherapy seems a successful approach for management of patients with WT and IVC tumor thrombus. Measurement of the cranio-caudal dimension of thrombus and its response to treatment should be considered in the surgical planning.

FXR1 expression domain in Wilms tumor

BACKGROUND/PURPOSE

Wilms tumor (WT) is the most common childhood kidney cancer globally. Our prior unbiased proteomic screen of WT disparities revealed increased expression of Fragile X-Related 1 (FXR1) in Kenyan specimens where survival is dismal. FXR1 is an RNA-binding protein that associates with poor outcomes in multiple adult cancers. The aim of this study therefore was to validate and characterize the FXR1 expression domain in WT.

METHODS

Quantitative FXR1 gene expression was compared between WT, adjacent, adult, and fetal kidney specimens. The cellular and subcellular expression domain of FXR1 was characterized across these tissues using immunoperoxidase staining. RNA-sequencing of FXR1 was performed from WT and other pediatric malignancies to examine its broader target potential.

RESULTS

FXR1 was detected in all clinical WT specimens evaluated (n = 82), and as a result appeared independent of demographic, histology, or adverse event. Specific cytosolic staining was strongest in blastema, intermediate and variable in epithelia, and weakest in stroma. When present, areas of skeletal muscle differentiation stained strongly for FXR1. qPCR revealed increased FXR1 expression in WT compared to adult and adjacent kidney (p < 0.0002) but was similar to fetal kidney (p = 0.648). RNA-sequencing revealed expression of FXR1 in multiple pediatric tumors, greatest in rhabdomyosarcoma and WT.

CONCLUSIONS

FXR1 was expressed consistently across this broad sampling of WT and most robustly in the primitive blastema. Notably, FXR1 labeled a specific self-renewing progenitor population of the fetal kidney.

Predictive factor for intraoperative tumor rupture of Wilms tumor

PURPOSE

For Wilms tumor, intraoperative tumor rupture with wide tumor spillage during surgical manipulation raises the classification to stage 3. Then, postoperative chemotherapy must be more intensive, and abdominal radiotherapy is added. Therefore, intraoperative tumor rupture should be avoided if possible. However, predictive factors for intraoperative tumor rupture have not been sufficiently described. Here we examined the risk factors for intraoperative tumor rupture.

METHODS

Patients with Wilms tumor who underwent treatment according to the National Wilms Tumor Study or the Japanese Wilms Tumor Study protocol at our institution were reviewed retrospectively. Collected cases were categorized into two groups: the ruptured group and the non-ruptured group. Risk factors for intraoperative tumor rupture, including the ratio of the tumor area to the abdominal area in a preoperative single horizontal computed tomography slice (T/A ratio), were investigated in both groups.

RESULTS

The two groups were not different in age, body weight, tumor laterality, sex, or histological distribution. The T/A ratio in the ruptured group was significantly higher than that in the non-ruptured group. Receiver operating characteristic curve analysis identified a discriminative value for a T/A ratio >0.5.

CONCLUSION

The T/A ratio can be a predictive factor for intraoperative tumor rupture of Wilms tumor.

K-Ras, H-Ras, N-Ras and B-Raf mutation and expression analysis in Wilms tumors: association with tumor growth

Nephroblastoma (Wilms tumor) is a kidney neoplasia, predominately occurring at very young age, resulting from the malignant transformation of renal stem cells. The Ras proto-oncogenes and B-Raf are members of an intracellular cascade pathway, which regulates cell growth and differentiation, and ultimately cancer development. Our objective was to determine the mutation rate and to measure the mRNA levels of the three Ras genes and of B-Raf in formalin-fixed paraffin-embedded tissue samples from 32 patients with nephroblastoma and 10 controls. No mutations were detected in the four studied genes among our Wilms tumors cases, while Ras and B-Raf expression was higher in malignant samples versus controls. Statistical analysis revealed a positive correlation of K-Ras (p < 0.001) and B-Raf (p = 0.006) with tumor size, a negative correlation of K-Ras (p = 0.041) and H-Ras (p = 0.033) with the percentage of tissue necrosis, and an association of N-Ras (p = 0.047) and B-Raf (p = 0.044) with tissue histology. From the above, we deduce that although Ras and B-Raf mutations are rare events in Wilms tumors, their expression pattern suggests that they play an important role in the development and progression of this malignancy.

Respiratory-gated bilateral pulmonary radiotherapy for Ewing's sarcoma and nephroblastoma in children and young adults: Dosimetric and clinical feasibility studies

PURPOSE

Bilateral pulmonary radiotherapy in children and young adults aims to reduce the recurrence of lung metastases. The radiation field includes liver tissue, which is sensitive to even low radiation doses. We investigated the feasibility of respiratory gating radiotherapy using voluntary deep inspiration breath hold and its toxicity in these patients.

PATIENTS AND METHOD

A retrospective clinical review was conducted for all patients who had undergone bilateral pulmonary radiotherapy, with or without deep inspiration breath hold, treated in our institution between October 1999 and May 2012. A dosimetric study was conducted on seven consecutive children using 4D-scan data on free-breathing and a SpiroDyn'RX-system-scan on deep inspiration breath hold. A radiation treatment of 20Gy was simulated.

RESULTS

Concerning the clinical study, seven patients of mean age 11.9 years (range: 4.9-21.1 years) were treated with free-breathing and ten patients of mean age 15.6 years (range: 8.6-19.7 years) were treated with deep inspiration breath hold for mainly Ewing sarcoma and nephroblastoma. Within six months of radiotherapy, all patients experienced mild liver toxicity (grade 1 or 2 altered levels of alanine/aspartate aminotransferase [n=8 of 9] or cholestasis [n=1 of 9]), which resolved completely with no difference between deep inspiration breath hold and free-breathing technique. Over a median follow-up of 2.6 years (range: 0.1-9.3 years), four patients died from disease progression (mean 1.5 years post-radiotherapy [range: 1.1-1.6 years]) and three experienced grade III-V lung toxicity. Concerning the dosimetric study, the irradiated liver volume was significantly lower with deep inspiration breath hold than free-breathing, for each isodose (V5: 73.80% versus 86.74%, P<0.05; V20: 5.70% versus 26.44%, P<0.05).

CONCLUSIONS

The dosimetric data of respiratory-gated bilateral pulmonary radiotherapy showed a significantly spare of normal liver tissue. Clinical data showed that this technique is feasible even in young children. However, no liver toxicity difference between deep inspiration breath hold and free-breathing was shown.

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.

•

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.

Technical aspects of Nephron-Sparing Surgery (NSS) in children with bilateral centrally located renal tumors

Bilateral Nephron-Sparing Surgery (NSS) is the gold standard as surgical treatment for children suffering from bilateral renal tumors. Whereas this approach is easy to achieve in peripheral tumors, it represents a relevant challenge in lesions that are centrally located. Involvement of the collecting system, localization deep within the renal parenchyma, and proximity to the central renal vessels are often difficult to deal with. A relevant number of patients thus receive unilateral total nephrectomy or undergo incomplete resections. However, surgery can often be performed successfully through experienced surgeons in centers of excellence, even though conditions for resection appear dismal on preoperative imaging. In this article, the authors describe technical aspects of Nephron-Sparing Surgery in complex conditions of bilateral pediatric renal tumors.

The rationale for nephron-sparing surgery in unilateral non-syndromic Wilms tumour

The central question of nephron-sparing surgery in unilateral non-syndromic Wilms tumour sits at a crossroads between surgery, oncology, and nephrology. There has been a significant paradigm shift in paediatric oncology towards reducing toxicity and addressing long-term treatment-related sequalae amongst childhood cancer survivors. After paediatric nephrectomy and 30-50 years of follow-up, 40% of patients will have chronic kidney disease, including 22% with hypertension and 23% with albuminuria. It is difficult to predict which patients will progress to develop hypertension, reduced glomerular filtration rate, albuminuria, and a higher cardiovascular risk. For these reasons, nephron-sparing surgery when it is technically feasible must be considered. To decrease the incidence of positive surgical margins (viable tumour present at a resection margin), incomplete lymph node sampling, and complications, these procedures should be performed at specialist and experienced reference centres. Based on the impacts of individual treatment pathways, survivors of childhood WT need to be followed through adulthood for early detection of chronic kidney disease, hypertension, and prevention of cardiovascular events.

Feasibility of using CT volume as a predictor of specimen weight in a subgroup of patients with low risk Wilms tumors registered on COG Study AREN03B2: implications for central venous catheter placement

OBJECTIVE

Patients with stage I Wilms tumor, age ≤ 2 years, tumor ≤ 550 g may not require therapy beyond nephrectomy. This study's aims were to determine: (1) if a linear relationship exists between tumor weight and computed tomography (CT) estimated volume; (2) describe the accuracy of a slope-intercept equation in estimating weight; and (3) determine the potential impact of weight estimation on port placement decisions.

MATERIALS AND METHODS

Tumor weight and port placement information were abstracted from 105 patients, age ≤ 2 years, with tumors ± 550 g, enrolled in COG AREN03B2. One radiologist estimated tumor size from CT scan. Prolate ellipse volume (PEV) was calculated, linear regression performed, slope-intercept equation calculated, equation estimated weight determined, and potential impact of the on port placement evaluated.

RESULTS

A strong relationship exists between PEV and weight (R(2) = 0.87). The slope-intercept equation for weight was: weight = 1.04(PEV) + 58.75. Overall median relative error for the equation was 0.9%, and -3% in tumors weighing 350-750 g. Fifty-five ports were placed, 29 in patients with tumor weight ≤ 550 g, and six not placed in patients with tumor weight > 550 g.

CONCLUSIONS

The relationship between PEV and weight produced a reliable weight prediction equation. Preoperative consideration of specimen weight may diminish the number of ports placed in this population.

Teratoid Wilms' tumor in a child: A report of a rare case

Teratoid Wilms’ tumor is an unusual variant of nephroblastoma in which heterologous tissue predominates. We report a case of teratoid Wilms’ tumor in a 2-year-old male. Right sided abdominal mass was the presenting complaint. Ultrasonography of the abdomen showed a mass in the right kidney. Histopathological examination revealed blastemal, epithelial, and mesenchymal components along with areas presenting heterologous elements. More than 75% predominance of squamous differentiation with the keratin pearl formation was observed. The patient underwent nephrectomy and was followed post-operatively for 1 year and was normal.

Dactinomycin-induced Hepatic Sinusoidal Obstruction Syndrome Responding to Treatment with N-acetylcysteine

Hepatic sinusoidal obstruction syndrome is commonly described in pediatric oncology as a complication of chemotherapy. It has also been occasionally reported in adult cancer patients. Treatment is largely supportive with fluid restriction. A 16-month-old girl with stage II Wilms tumor receiving post-nephrectomy chemotherapy with dactinomycin and vincristine developed hepatic sinusoidal obstruction syndrome with painful hepatomegaly, ascites with significant weight gain, grossly deranged liver function, severe thrombocytopenia, and reversal of blood flow in the portal vein on Doppler sonography. Treatment with N-acetylcysteine was followed by complete resolution of clinical signs and amelioration of laboratory abnormalities within 72 hours of treatment. N-acetylcysteine is a safe and probably an effective treatment for dactinomycin-induced hepatic sinusoidal obstructive syndrome.

Autophagy Inhibition in Childhood Nephroblastoma and the Therapeutic Significance

BACKGROUND

Autophagy is a physiological pathway characterized by lysosomedependent self-digestion to recycle damaged or superfluous cellular content. Deregulation of autophagy hampers the maintenance of cellular homeostasis and contributes to tumorigenesis. However, during anticancer therapy, autophagy activation contributes to development of resistance. Thus autophagy has been recognized as an important pathway and a therapeutic target in cancer. Nephroblastoma (Wilm's tumor) is a common childhood malignancy. The role of autophagy in nephroblastoma is largely uninvestigated.

OBJECTIVE

This study is to investigate the change of autophagy level in nephroblastoma, and whether autophagy could be a therapeutic target in anaplastic nephroblastoma.

METHOD

In clinical samples of childhood nephroblastoma, autophagy activity was evaluated by the expressions of selected autophagy markers as well as the presence of autophagosome ultrastructure. Use of autophagy inhibitors alone and in combination with conventional chemotherapeutics, was studied both in vivo and in vitro.

RESULTS

In nephroblastoma, there was decrease in the Beclin 1 level and the number of autophagosomes, suggesting autophagy inhibition. Furthermore, in two anaplastic nephroblastoma cell lines, G401 and SK-NEP1, autophagy inhibitors further enhanced the efficacy of conventional chemotherapeutics including vincristine and cisplatin. In G401 tumor model established in nude mice, combinational use of chloroquine, an inhibitor of autophagy degradation, further decreased the tumor mass compared with single use of the chemotherapeutics vindesine, although no statistical significance was achieved.

CONCLUSION

Our results suggest that autophagy deregulation is involved in nephroblastoma, and targeting autophagy can serve as a potential adjuvant strategy for the highly malignant cases.

Prominent entrapment of respiratory epithelium in primary and metastatic intrapulmonary non-epithelial neoplasms: a frequent morphological pattern closely mimicking adenofibroma and other biphasic pulmonary lesions

As one of the most common target organs for hematogenous spread from diverse cancers, biopsy interpretation of lung tumors is complicated by the challenging question of primary versus metastatic and by frequent entrapment of native respiratory glands. Nevertheless, the literature dealing with this issue is surprisingly sparse and no single study has been devoted to this topic. We reviewed 47 surgical lung specimens of non-epithelial neoplasms (38 metastases, mainly from sarcomas and 9 primary lesions) for frequency and pattern of intralesional epithelial entrapment. Respiratory epithelium entrapment was noted in 23/47 (49%) cases (diffuse in 15 and peripheral in 8). Entrapped glands frequently showed prominent regenerative and reactive changes mimicking neoplastic glands. Based on cellularity of the mesenchymal component and the extent, distribution and shape of entrapped respiratory glands, four morphological patterns were recognized: paucicellular sclerosing low-grade neoplasms containing leaflet-like glands indistinguishable from adenofibroma and fibroepithelial hamartomas (n = 11), and biphasic cellular lesions mimicking adenomyoepithelioma (n = 1), biphasic synovial sarcoma (n = 2), and pleuropulmonary blastoma (n = 1). Only a single genuine pulmonary adenofibroma was identified. This study highlights frequent respiratory epithelium entrapment in diverse non-epithelial lung tumors, both primary and metastatic. Recognition of this finding and use of adjunct IHC combined with clinical history should help to avoid misinterpretation as primary pulmonary biphasic neoplasm or as harmless adenofibroma. The vast majority of morphologically defined lung adenofibromas represent adenofibroma-like variants of histogenetically diverse entities so that a diagnosis of adenofibroma should be rendered only very restrictively and then as a diagnosis by exclusion.

Inhibitory effect of Par-4 combined with cisplatin on human Wilms' tumor cells

Wilms' tumor is associated with a high treatment success rate, but there is still a risk of recurrence. Cisplatin, which is one of the chemotherapeutic agents used for its treatment, is associated with a very high rate of resistance. Par-4 (prostate apoptosis response 4) is a tumor suppressor, which is capable of sensitizing tumor cells to chemotherapy. Therefore, the aim of this study was to determine whether combined treatment with Par-4 and cisplatin is effective for inhibiting growth of Wilms' tumor. Wilms' tumor and control cell samples were collected and analyzed by immunofluorescence assay and immunohistochemistry. Total proteins extracted from cultured cells were analyzed using western blotting and flow cytometry. In addition, a mouse xenograft model was established. We discovered significantly low expression of Par-4 in the tumor tissue, which was positively correlated with high expression of GRP78 (glucose-regulated protein 78). In addition, we found that ectopic Par-4 co-localized with cell surface GRP78 and induced high expression of the endoplasmic reticulum proteins ATF4 and BAX, which activated the endoplasmic reticulum apoptosis pathway. Moreover, treatment with ectopic Par-4 and cisplatin suppressed xenograft growth in nude mice. In conclusion, our results showed that Par-4 overexpression and cisplatin had a synergistic effect on SK-NEP-1 cells, as a result of which cell growth was inhibited and cellular apoptosis was induced. Thus, in vitro and in vivo upregulation of Par-4 expression is indispensable for the trafficking of GRP78 to the cell membrane and subsequent apoptosis of cancer cells.

Knockdown of lncRNA HAGLROS inhibits metastasis and promotes apoptosis in nephroblastoma cells by inhibition of autophagy

Nephroblastoma, or Wilms tumor, is a primary renal malignant tumor that easily occurs in children. Previous studies have revealed the regulatory functions of LncRNA in nephroblastoma. LncRNA HAGLROS functions as a tumor promotor in various cancers including hepatocellular carcinoma, ovarian cancer and colorectal cancer. In this study, the HAGLROS expression in nephroblastoma cells was assayed through qRT-PCR. Cell proliferation assessment employed CCK-8. Moreover, the migration and invasion of cells were examined separately through wound healing and transwell assay. Moreover, flow cytometric analysis and Western blot assay were applied to evaluate cell apoptosis. Rapamycin and 3-methyladenine were used to serve as autophagy activator or inhibitor, respectively. In addition, autophagy was identified by immunofluorescence staining and Western blot analysis. Experiment results showed that HAGLROS expressed highly in nephroblastoma cell lines. HAGLROS knockdown prevented cells from proliferating, and also showed suppressive impact on migration and invasion in HFWT cells. In addition, knockdown of HAGLROS showed a facilitative effect on apoptosis and an inhibitory effect on autophagy. Stimulation of autophagy alleviated HAGLROS silencing-induced apoptosis, while inhibition of autophagy reversed the effect in nephroblastoma cells. In summary, our results revealed that HAGLROS executed an oncogenic role in the progress of nephroblastoma, offering a new perspective on the strategy for nephroblastoma therapy.

[Wilms' tumour: A review of 15 years recent experience]

INTRODUCTION

Wilms' tumour is the most frequent renal tumour in children. Multi-modal treatment includes chemotherapy and surgery, with or without radiotherapy. The survival is excellent, with rates exceeding 90%. A review is presented on our experience over the last 15 years of treating Wilms' tumour in Hospital Niño Jesús, Madrid.

PATIENTS AND METHODS

A retrospective study was conducted on 40 consecutive paediatric patients diagnosed with nephroblastoma between 2002 and 2016 in the Hospital Niño Jesús in Madrid. The clinical characteristics, diagnostic methods, treatment, and follow-up were analysed.

RESULTS

Of the 40 patients, 23 were boys, with a median age at diagnosis of 2.5 years (range, 4 months-15 years). Three patients underwent initial nephrectomy, three received a fine needle aspiration biopsy, followed by chemotherapy, and 34 patients started pre-operative chemotherapy directly. The median follow-up of the patients was 6.75 years (range, 10 months - 13.92 years). Two patients died from disease progression. There were no treatment-related deaths. Overall survival and event-free survival at 5 years was 94.6±3.7% and 89.4±5%, respectively.

CONCLUSION

Wilms' tumour treatment is a success of modern medicine, currently achieving a survival rate of 95% in our series.

Imaging spectrum of primary malignant renal neoplasms in children

Wilms' tumor (WT) is the most common abdominal tumor in children. Many pediatric renal tumors in the past were categorized as WT; however, in recent years, several specific renal tumors have been recognized as distinct pathological entities. The age and clinical presentation of the child and distinctive imaging features may help in reaching a specific diagnosis in most cases. This is important as it has implications on the pre-operative diagnostic work-up and prognosis of the child. However, it is often not possible to differentiate one from the other pediatric renal tumor on the basis of imaging alone, and the final diagnosis is often made at histological examination of the surgical specimen. This article reviews the imaging features of primary malignant renal neoplasms in children along with their clinical presentation and pathological features.

Heart-sparing volumetric modulated arc therapy for whole lung irradiation

PURPOSE

Whole lung irradiation (WLI) is indicated for subgroups of patients with lung metastases from Wilms' tumor (nephroblastoma). WLI has traditionally been performed with an anterior/posterior field arrangement with poor potential for heart sparing; thus, new techniques are desirable to achieve a lower dose to the heart.

MATERIALS AND METHODS

We utilized volumetric modulated arc therapy (VMAT) for WLI with 18 Gy in a patient with metastatic nephroblastoma. The planning results were compared against a three-dimensional (3D) conformal plan.

RESULTS

VMAT resulted in adequate target volume coverage with the prescribed dose. Mean heart dose was 10.2 Gy. The dose to organs at risk (OAR) was generally more favorable with VMAT when compared with a 3D-conformal radiotherapy plan.

DISCUSSION

WLI with VMAT provides superior sparing of OARs and especially a considerably lower dose to the heart.

Health disparities among tennessee pediatric renal tumor patients

BACKGROUND/PURPOSE

Wilms tumor (WT) poses a cancer health disparity to black children globally, which has not been evaluated thoroughly for other pediatric renal cancers. We aimed to characterize health disparities among Tennessee children treated for any renal cancer.

METHODS

The Tennessee Cancer Registry (TCR) was queried for patients ≤18 years having any renal cancer (n = 160). To clarify treatment and outcomes, we performed a retrospective cohort study of pediatric renal cancer patients in our institutional cancer registry (ICR; n = 121). Diagnoses in both registries included WT, Sarcoma/Other, and Renal Cell Carcinoma. Wilcoxon/Pearson, Kaplan-Meier, and logistic regression were completed.

RESULTS

In both registries, WT comprised the most common renal cancer and youngest median age. Sarcoma was intermediate in frequency and age, and RCC was least common, having the oldest age (p < 0.001). In the TCR, black patients comprised 26% of all patients, presented more commonly with distant disease than white patients (37% v. 16%; p = 0.021), and showed worse overall survival (73% v. 89%; p = 0.018), while the ICR showed similar survival between race groups (92% v. 93%, p = 0.868). Sarcoma and metastases were independent predictors of death in both registries (p ≤ 0.002).

CONCLUSIONS

Black children in Tennessee presented with more advanced disease and experienced worse survival when combining all renal cancer types, particularly RCC and Sarcoma. When treated at a comprehensive pediatric cancer center, these survival disparities appear diminished.

TYPE OF STUDY

Prognostic study.

LEVEL OF EVIDENCE

Level II (retrospective cohort).

Management and outcome of pediatric metastatic Wilms' tumor at the National Cancer Institute, Egypt

BACKGROUND

Wilms' tumor (WT) is the most common renal malignant tumor of childhood. Metastatic WT has a worse prognosis than localized disease. This study aims to assess the clinical outcome and different prognostic factors that influence treatment outcome of pediatric metastatic WT cases treated at National Cancer Institute (NCI), Egypt, between January 2008 and December 2015. Medical records were retrospectively reviewed for clinical, radiological and histopathological data, treatment received, and survival outcome.

RESULTS

In the specified study period, 24/103 (23.3%) patients with WT were metastatic at presentation. The mean age was 5.25 ± 2.87 years (range 2.0-12.7). Abdominal swelling/mass was the commonest presentation (70.8%). Only 3 patients (12.5%) had combined lung and liver metastases while 21 patients (87.5%) had pulmonary-only metastases. All patients had favorable histology tumors with no anaplasia. Nine patients (37.5%) underwent upfront nephrectomy. Majority of patients (91.7%) had local stage III disease. Surgical complications were reported in 4 patients; 3 of them had up-front nephrectomy. Only 7/21 patients achieved rapid complete response of pulmonary nodules after 6 weeks of chemotherapy (CTH), and they had a better survival outcome. Patients were followed up till December 2017. Thirteen patients (54.1%) experienced events during the study period including 5 relapses, 6 cases with disease progression, and 2 patients died out of sepsis. The 3-year event-free and overall survival rates were 48.2% and 54.2%, respectively.

CONCLUSION

Neo-adjuvant CTH followed by delayed nephrectomy seems more suitable approach in our institute. Pulmonary response to neo-adjuvant CTH appears to be a strong predictor for outcome.

Multicystic dysplastic kidney: Assessment of the need for renal scintigraphy and the safety of conservative treatment

OBJECTIVES

To assess the need for implementing renal scintigraphy in the diagnosis of the multicystic dysplastic kidney (MCDK) and the safety of its conservative treatment.

MATERIAL AND METHODS

A retrospective study of patients with unilateral MCDK was conducted at our centre from January 2005 to August 2015. We calculated the positive predictive value (PPV) of ultrasonography, taking renal scintigraphy and pathology as the gold standard. We calculated a survival curve according to the Kaplan-Meier method to assess the annual probability of spontaneous resolution of the multicystic kidney.

RESULTS

Fifty-six patients were identified, 48 (85.7%) of whom had a prenatal diagnosis. Thirty eight (67.9%) of the patients were males, and the left side was affected in 33 (58.9%) of the patients. We observed associated urological abnormalities in 22 (39.29%) patients, with vesicoureteral reflux the most common (8, 14.29%). Seven patients (12.5%) developed renal failure. Forty-nine (87.5%) patients developed compensatory contralateral renal hypertrophy. Of the 33 patients who underwent surgery, the pathology results confirmed the MCDK diagnosis in 32. Compared with scintigraphy and pathology, the PPV of ultrasonography was 100% and 97%, respectively. The rate of spontaneous involution was 5.4% at 3 months of life, 11.3% at 2 years and 38.4% at 5 years.

CONCLUSIONS

In our experience, the conservative treatment of MCDK, until at least 5 years of age, is safe. Our data suggest that performing scintigraphy is not required for these patients, which means lower radiation exposure, as well as financial savings.

The association between nephroblastoma-specific outcomes and high versus low volume treatment centers

BACKGROUND

Though the volume-outcome relationship has been well-established in adults, low mortality rates and small sample sizes have precluded definitive demonstration in children. This study compares treatment-specific factors for children with nephroblastoma at high (HVC) versus low volume centers (LVC).

METHODS

We performed a retrospective cohort study comparing patients ≤18years with unilateral nephroblastoma treated at HVCs and LVCs using the National Cancer Data Base (1998-2012). Definitions of HVCs included performing above the median, the upper two quartiles, and the highest decile of nephroblastoma resections. Outcomes included nodal sampling, margin status, time to chemotherapy and radiation, and survival. Statistical analyses included χ², t-tests, generalized linear, and Cox regression models (p<0.05).

RESULTS

Of 2911 patients from 210 centers, 1443 (49.6%) were treated at HVCs. There was no difference in frequency of preoperative biopsy or days to radiation (p>0.05). High volume centers were more likely to perform nodal sampling (RR 1.04, 95%CI 1.01-1.08) and had fewer days to chemotherapy (RR 0.80, 95%CI 0.69-0.93). Five-year survival was similar (HVC: 0.93, 95%CI 0.92-0.94; LVC: 0.93, 95%CI 0.91-0.94).

CONCLUSIONS

HVCs were more likely to perform nodal sampling and had fewer days to chemotherapy. There was no difference in days to radiation or survival between centers.

LEVEL OF EVIDENCE

Level II (retrospective prognosis study).

Implications of cell division cycle associated 4 on the Wilm's tumor cells viability via AKT/mTOR signaling pathway

Objective

The aim of present report was to elucidate the effect of cell division cycle associated 4 (CDCA4) on the proliferation and apoptosis of Wilm’s tumor cells, and to further evaluate its underlying mechanism.

Methods

The expression profiles of CDCA4 and clinical information of Wilm’s tumor patients were obtained from public Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database portal. Real-time qPCR and western blot analyses were utilized to determine the expression levels of CDCA4. Gain- and loss-of-function of CDCA4 assays were conducted with transfection technology to investigate the biological role of CDCA4 in Wilm’s tumor cells. Cell counting kit 8 and flow cytometer assays were employed to examine the effect of CDCA4 on the cells proliferation and apoptosis. Protein expression levels of indicated markers in each group of Wilm’s tumor cells were measured by western blot.

Results

The transcriptional expression of CDCA4 was drastically upregulated in Wilm’s tumor tissues according to the public TARGET database and in Wilm’s tumor cells. The cells viability was remarkably reduced whereas the cells apoptosis was increased in CDCA4-knockdown group compared with negative control group. However, CDCA4-overexpression group promoted the cells proliferation and suppressed the cells apoptosis. Furthermore, the protein expression levels of p-AKT, p-mTOR, and Cyclin D1 were significantly reduced after depletion of CDCA4, whereas overexpression of CDCA4 dramatically elevated these markers’ expression levels.

Conclusions

CDCA4 is highly expressed in Wilm’s tumor and promoted the proliferation whereas inhibited the apoptosis of Wilm’s tumor cells through activating the AKT/mTOR signaling pathway.

Immunohistochemical expression of P53 protein in nephroblastoma: a predictor of unfavorable prognosis

OBJECTIVE

Immunohistochemical expression of P53 protein is so closely related to status of mutation of P53 gene which is tightly linked with pathogenesis of nephroblastoma or Wilms tumor. This study aims to determine the immunohistochemical expression of P53 protein and its predictors in formalin-fixed paraffin-embedded tissue blocks of patients with nephroblastoma.

MATERIALS AND METHODS

A series of 83 histologically diagnosed cases of nephroblastoma from formalin-fixed paraffin-embedded tissue blocks archived at the Department of Pathology, Makerere University, in Kampala, Uganda, were analyzed. Monoclonal anti-p53 antibody (DO-7, DAKO) was used to assess the expression of P53 protein expression. Multivariable logistic regression analysis was performed to determine the predictors of P53 protein immunohistochemical expression, and statistical significance was considered when p-value was less than 0.05.

RESULTS

Most (42.2%, n = 35) of the cases were in advanced tumor stages (III-V), and almost one-quarter (21.7%, n = 18) of the cases were in high-risk group. The immunohistochemical expression of P53 protein was (8.4%, n = 7), and there were more (83.3%, n = 5) positive anaplastic cases for P53 protein compared with (2.6%, n = 2) of P53 expression for non-anaplastic cases. High risk (AOR = 3.42, 95% CI = 7.91-12.55, p = 0.037) and anaplasia (AOR = 1.41, 95% CI = 13.85-4.46, p = 0.001) were potential predictors of immunohistochemical expression of P53 protein.

CONCLUSION

Most of patients with nephroblastoma in resources-limited settings are diagnosed with advanced clinical stages. Association of P53 protein with anaplasia found in this study indicates the possibility of having novel target therapy for treatment of patients with anaplastic form of nephroblastoma with a focus of identifying molecules that lead to its suppression in such subpopulations of patients with nephroblastoma.

Preoperative chemotherapy and local stage III in nephroblastoma

The evolution of Nephroblastoma (WT) treatment over the last decades has been one major success around the world. Despite pursuing different upfront treatment approaches the Children's Oncology Group (COG, former National Wilms Tumor Study Group, NWTSG) and the International Society of Paediatric Oncology's Renal Tumor Study Group (SIOP-RTSG) show the same outcome. Treatment starts with preoperative chemotherapy in SIOP-RTSG compared to initial surgery in COG. Response to chemotherapy can be used as a stratification parameter. This allows treating patients with blastemal subtype more aggressively resulting in a better event free survival (EFS). Moreover the percentage of patients with local stage III is less in SIOP-RTSG than in COG studies. Lymph node involvement, in NWTS 5 together with residual microscopic disease, results in a lower EFS in both study groups. But overall survival (OS) is not different comparing patients with or without positive lymph nodes (LN). No other reason for stage III has a significant impact on outcome. The role of radiotherapy for local tumor control in stage III is important, but the radiation dose needs to be questioned as 10.8 Gy used in COG is as efficient as 15 Gy in SIOP-RTSG protocols. In addition in part of low income countries radiotherapy can not be given due to a lack of radiation facilities. Nevertheless some patients are cured without irradiation. The analysis of local stage III patients underlines the importance of preoperative chemotherapy and the need for molecular studies to better stratify patients according to their individual risk.