Twenty-five year follow-up of childhood Wilms tumor: a report from the Childhood Cancer Survivor Study

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 New Proton Therapy Solution Provides Superior Cardiac Sparing Compared With Photon Therapy in Whole Lung Irradiation for Pediatric Tumor Patients

Objective

Whole lung irradiation (WLI) plays a crucial role in local control in pediatric patients with lung metastases and improves patient survival. The intention of this research was to explore the advantage of cardiac sparing between photons and protons during WLI. We also propose a new solution for cardiac sparing with proton techniques.

Methods

Eleven patients with pediatric tumors and pulmonary metastasis treated with 12 Gy WLI (all received volumetric-modulated arc therapy (VMAT)) in our institute between 2010 and 2019 were retrospectively selected. Each patient was replanned with intensity-modulated radiation therapy (IMRT), helical tomotherapy (HT), and two intensity-modulated proton radiotherapy (IMPT) plans (IMPT-1 and IMPT-2). IMPT-1 considered the whole lung as the planning target volume (PTV), utilizing the anteroposterior technique (0/180°). IMPT-2 was a new proton solution that we proposed in this research. This approach considered the unilateral lung as the PTV, and 3 ipsilateral fields were designed for each lung. Then, IMPT-2 was generated by summing two unilateral lung plans. The primary objective was to obtain adequate coverage (95% of the prescription dose to the PTV) while maximally sparing the dose to the heart. The PTV coverage, conformity index (CI), homogeneity index (HI), and dose–volume statistics of the heart and substructures were assessed by means of the averages of each comparison parameter.

Results

All treatment techniques achieved the target volume coverage required by clinical practice. HT yielded the best coverage and homogeneity for the target structure compared with other techniques. The CI from IMRT was excellent. For photon radiation therapy, the HT plan afforded superior dose sparing for the V₅, V₆, V₇, V₈, and D_mean of the heart and D_mean of the right ventricle (RV). IMRT displayed the most notable dose reductions in the V₉, V₁₀, V₁₁, and V₁₂ of the heart and D_mean of the right atrium (RA). The VMAT plan was the least effective on the heart and substructures. However, compared with photon radiation therapy, IMPT-1 did not show an advantage for heart protection. Interestingly, IMPT-2 provided significant superiority in cardiac sparing, including maximum dose sparing for the V₅, V₆, V₇, V₈, V₉ and D_mean of the heart and D_mean of the RA, RV, left atrium (LA) and left ventricle (LV) compared to all other techniques.

Conclusions

Considering the complex anatomical relation between target volumes and organs at risk (OARs), IMPT can provide a dose advantage for organs located outside of the target area rather than within or surrounding the area. It is hoped that advances in proton therapy (PT) plan design will lead to further improvements in radiotherapy approaches and provide the best treatment choice for individual patients.

Integrated bioinformatic analysis identifies COL4A3, COL4A4, and KCNJ1 as key biomarkers in Wilms tumor

Wilms tumor (WT) is one of the most common pediatric solid tumors, affecting 1 in 10,000 children, worldwide. A subset of WT patients has poor prognosis, which is associated with a high risk of advanced and/or recurrent disease. Therefore, candidate markers are urgently needed for the diagnosis and effective treatment of WT. We evaluated three mRNA microarray datasets to identify the differences between normal kidney tissue and WT tissue. Gene expression profiling revealed 130 differentially expressed genes (DEGs). Enrichment analysis and gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed for the DEGs. Subsequently, we established a protein-protein interaction (PPI) network to reveal the associations among the DEGs and selected 10 hub genes, all of which were downregulated in WT. The expression of COL4A3, COL4A4, KCNJ1, MME, and SLC12A1 in WT tissues was significantly lower than that in normal renal tissues. Survival analyses using the Kaplan-Meier method showed that patients with WT and low expression of COL4A3, COL4A4, and KCNJ1 exhibited remarkably poor overall survival. The correlations among COL4A3, COL4A4, and KCNJ1 in WT were analyzed using cBioPortal; COL4A3, COL4A4, and KCNJ1 were positively correlated with each other. Thus, these genes were considered clinically significant and might therefore play important roles in carcinogenesis and the development of WT.

Surgical Management of Wilms Tumor (Nephroblastoma) and Renal Cell Carcinoma in Children and Young Adults

This article reviews the epidemiology, pathophysiology, clinical presentation, and multimodality management of Wilms tumors and renal cell carcinoma in pediatric and young adults. Key renal Société Internationale d'Oncologie Pédiatrique and Children Oncology Group studies are presented. The article reviews the common staging systems and risk-adapted treatment strategies with particular attention to the surgical management.

Cervical Spine Chondrosarcoma in an Adult with a History of Wilms Tumor

INTRODUCTION

We report the first case of cervical spine chondrosarcoma in a Wilms tumor survivor.

CASE DESCRIPTION

A 52-year-old female patient presented with myelopathic symptoms including poor balance, difficulty walking, and numbness of both feet. A magnetic resonance imaging of the spine showed a mass at the right C7-T1 foramen causing significant cord compression. The patient's symptoms improved after posterior decompression and fusion with excision of the tumor.

CONCLUSION

Through our experience with this case, we would like to suggest a possible unknown genetic syndrome predisposing patients with Wilms tumor to chondrosarcoma as secondary neoplasms. We would also like to re-emphasize the need for vigilance when assessing patients with a history of Wilms tumor.

Lithocholic bile acid induces apoptosis in human nephroblastoma cells: a non-selective treatment option

Lithocholic bile acid (LCA) has been reported to selectively kill cancer cells within many tumor cell lines including neuroblastoma or glioblastoma. Wilms’ tumor shares similarities with neuro- and glioblastoma. Hence, the aim of the study was to evaluate the effects of LCA on nephroblastoma. To test the effects of LCA, nephroblastoma cell line WT CLS1 was used. SK NEP1 was tested as well. It was originally classified as a nephroblastoma cell line but was meanwhile reclassified as an ewing sarcoma cell line. As control cell lines HEK 293 from embryonic kidney and RC 124 from adult kidney tissue as well as podocytes were used. The effects were evaluated using proliferation assay, caspase activity assay, FACS and Western blot. LCA showed a dose and time-dependent selective effect inducing apoptosis in nephroblastoma cells. However, these effects were not limited to the nephroblastoma cell line but also affected control kidney cell lines and the sarcoma cells; only podocytes are significantly less affected by LCA (at dosages < 200 µm). There were no significant differences regarding the TGR5 receptor expression. The study showed that LCA has a strong, yet unselective effect on all used in vitro cell-lines, sparing the highly differentiated podocytes in lower concentrations. Further studies are needed to verify our results before dismissing LCA as an anti-cancer drug.

Psychological, educational, and social late effects in adolescent survivors of Wilms tumor: A report from the Childhood Cancer Survivor Study

OBJECTIVE

To delineate the impact of treatment exposures and chronic health conditions on psychological, educational, and social outcomes in adolescent survivors of Wilms tumor.

METHODS

Parent reports from the Childhood Cancer Survivor Study were analyzed for 666 adolescent survivors of Wilms tumor and 698 adolescent siblings. Adjusting for race and household income, survivors were compared to siblings on the Behavior Problems Index and educational outcomes. Multivariable modified Poisson regression estimated relative risks (RR) for therapeutic exposures and chronic health conditions (CTCAE 4.03 graded) among survivors, adjusting for sex, race, income, and age at diagnosis.

RESULTS

Compared to siblings, adolescent survivors of Wilms tumor were more likely to take psychoactive medication (9.4% vs. 5.1%, p < 0.001) and utilize special education services (25.5% vs. 12.6%, p < 0.001) but did not differ significantly in emotional and behavioral problems. Survivors were less likely to be friendless (7.2% vs. 10.1%, p = 0.04) but were more likely to have difficulty getting along with friends (14.5% vs. 7.8%, p < 0.001). Among survivors, use of special education services was associated with abdomen plus chest radiation (RR = 1.98, CI:1.18-3.34). Those with grade 2-4 cardiovascular conditions had higher risk for anxiety/depression (RR = 1.95, CI:1.19-3.19), headstrong behaviors (RR = 1.91, CI:1.26-2.89), and inattention (RR = 1.56, CI:1.02-2.40).

CONCLUSIONS

Adolescent survivors of Wilms tumor were similar to siblings with respect to mental health concerns overall but were more likely to require special education. Monitoring of psychosocial and academic problems through adolescence is warranted, especially among those treated with radiation to the abdomen plus chest or with cardiac conditions.

Pediatric craniospinal irradiation with a short partial-arc VMAT technique for medulloblastoma tumors in dosimetric comparison

Background

This study aimed to contrast four different irradiation methods for pediatric medulloblastoma tumors in a dosimetric comparison regarding planning target volume (PTV) coverage and sparing of organs at risk (OARs).

Methods

In sum 24 treatment plans for 6 pediatric patients were realized. Besides the clinical standard of a 3D-conformal radiotherapy (3D-CRT) treatment plan taken as a reference, volumetric modulated arc therapy (VMAT) treatment plans (“VMAT_AVD” vs. “noAVD” vs. “FullArc”) were optimized and calculated for each patient. For the thoracic and abdominal region, the short partial-arc VMAT_AVD technique uses an arc setup with reduced arc-length by 100°, using posterior and lateral beam entries. The noAVD uses a half 180° (posterior to lateral directions) and the FullArc uses a full 360° arc setup arrangement. The prescription dose was set to 35.2 Gy.

Results

We identified a more conformal dose coverage for PTVs and a better sparing of OARs with used VMAT methods. For VMAT_AVD mean dose reductions in organs at risk can be realized, from 16 to 6.6 Gy, from 27.1 to 8.7 Gy and from 8.0 to 1.9 Gy for the heart, the thyroid and the gonads respectively, compared to the 3D-CRT treatment method. In addition we have found out a superiority of VMAT_AVD compared to the noAVD and FullArc trials with lower exposure to low-dose radiation to the lungs and breasts.

Conclusions

With the short partial-arc VMAT_AVD technique, dose exposures to radiosensitive OARS like the heart, the thyroid or the gonads can be reduced and therefore, maybe the occurrence of late sequelae is less likely. Furthermore the PTV conformity is increased. The advantages of the VMAT_AVD have to be weighed against the potentially risks induced by an increased low dose exposure compared to the 3D-CRT method.

Large variation in assessment and outcome definitions to describe the burden of long-term morbidity in childhood cancer survivors: A systematic review

We systematically reviewed outcome assessment methods, outcome classification, and severity grading of reported outcomes in studies investigating the burden of physical long-term morbidity in childhood cancer survivors (CCS). A MEDLINE and EMBASE search identified 56 studies reporting on three or more types of health conditions in 5-year CCS, for which information was extracted on outcome types and classification, methods of outcome ascertainment, and severity grading. There was substantial variability in classification and types of health conditions reported and in methods of outcome ascertainment. Only 59% of the included studies applied severity grading, mainly the common terminology criteria of adverse events. This large variation in assessment and definition of the burden of physical long-term morbidity in CCS challenges interpretation, comparison, and pooling data across studies. Global collaboration is needed to standardize assessments and harmonize definitions of long-term physical morbidity and associated outcomes in childhood cancer survivorship research.

Inferior Vena Cava Syndrome: A Rare Complication

Inferior vena cava syndrome is rare and often difficult to diagnose because of its rarity and consequent low suspicion.

We describe the case of a 28-year-old female patient with a history of nephroblastoma of the right kidney, stage IV, with a favourable histology with epidural metastasis (D5–D9), diagnosed at 3 years of age. The patient underwent treatment with surgery, chemotherapy and radiotherapy.

The patient suffered from sudden low back pain worsening over 2 weeks, with progressive inability to walk. The pain radiated to the front of the thighs. Concomitantly, oedema of the lower limbs with cephalocaudal progression was observed. At admission to our institution, the physical examination showed peripheral oedema, abdominal wall venous collaterals, an inability to walk due to low back pain in the supine position, with no neurological deficits. Lumbar MRI showed exuberant epidural venous congestion. The hypothesis of inferior vena cava thrombosis (IVCT) was considered and confirmed by angio-CT.

IVCT is prevalent in patients with congenital anomalies of the inferior vena cava, occurring in approximately 60–80% of these cases, and most published series on inferior vena cava syndrome refer to thrombotic complications in this subgroup of patients. There are currently no guidelines defined or validated to guide the diagnosis and approach to IVCT. With this case, we would like to draw attention to a rare disease that should be suspected in all patients with inferior vena cava disease, whether resulting from congenital disease or after surgical procedures.

Long-term renal function after treatment for unilateral, nonsyndromic Wilms tumor. A report from the St. Jude Lifetime Cohort Study

BACKGROUND

The impact of specific treatment modalities on long-term renal function and blood pressure among adult survivors of Wilms tumor (WT) has not been well documented.

METHODS

Among 40 WT survivors and 35 noncancer controls, we estimated the glomerular filtration rate (eGFR) using the Chronic Kidney Disease-Epidemiology (CKD-EPI) equations with and without cystatin C, obtained 24-hour ambulatory blood pressure readings, and, among survivors only, measured ^99m Tc diethylenetriamine pentaacetic acid (DTPA) plasma clearance. Survivors were treated with unilateral nephrectomy and nonnephrotoxic chemotherapy. Twenty received whole abdomen radiation therapy (WART) [median -16.5 Gray (Gy)], and 20 received no radiation therapy. Pairwise comparisons between survivors treated with and without WART, and each group to controls were performed using two-sample t tests.

RESULTS

Twenty-six (65%) WT survivors were female, and 33 (83%) were non-Hispanic white. GFR estimated with creatinine or creatinine + cystatin C was decreased among irradiated survivors compared with controls. No irradiated or unirradiated participant had an eGFR (creatinine + cystatin C) < 60 mL/min/1.73 m² . The prevalence of hypertension was significantly increased among unirradiated (25%) and irradiated survivors (35%) compared with controls (0%). Of the 24-hour ambulatory blood pressure monitoring parameters evaluated, only mean sleep period diastolic blood pressure load of those who received WART was significantly different from that of controls.

CONCLUSIONS

Chronic kidney disease was infrequent in long-term survivors of unilateral nonsyndromic WT, whether treated with WART or no radiation. The prevalence of hypertension was increased in both groups compared with controls, emphasizing the need for ongoing monitoring of renal and cardiovascular health.

Wilms tumor: a review of current surgical controversies

Overall survival (OS) for children with Wilms tumor (WT) currently stands at around 90%. This is markedly improved from the survival rates of around 30% reported in the middle of the last century. This improvement is due to the development of multimodal treatment for this disease, based on the evidence yielded through international collaboration on trials conducted by the Société Internationale d'Oncologie Pédiatrique (SIOP) and the Children’s Oncology Group (COG). In this article, we review some of the current surgical controversies surrounding the management of WT.

Renal tumours in Australian children: 30 years of incidence, outcome and second primary malignancy data from the Australian Childhood Cancer Registry

AIM

This paper describes the incidence and outcomes of childhood renal malignancies in Australia using national population-based data from the Australian Childhood Cancer Registry.

METHODS

De-identified data for children (0-14 years) diagnosed with renal malignancies from 1983 to 2015 inclusive were extracted. Cause-specific (CSS) and event-free survival up to 20 years from diagnosis were estimated using the cohort method. Adjusted excess mortality hazard ratios were calculated using a multivariable flexible parametric survival model. Details relating to second primary malignancies (SPMs) were also examined.

RESULTS

There were 1046 children diagnosed with renal malignancies in Australia between 1983 and 2015 (91% nephroblastoma), generating an annual age-standardised incidence rate of 8 per million children, which remained constant over the study period. CSS was 89% (95% confidence interval = 87-91%) and 88% (86-90%) at 5 and 20 years, respectively, and 5-year event-free survival was 82% (80-84%). Five-year CSS did not change over the study period and was highest for nephroblastoma (91%). Of the 94% of patients achieving remission, 15% relapsed and subsequent 5-year CSS was 49% (40%-58%). Eleven children were diagnosed with SPM (standardised incidence ratio = 2.9, 95% confidence interval = 1.6-5.3, P < 0.001), and five of them (45%) died within 5 years of the second diagnosis.

CONCLUSIONS

Children treated for renal malignancies in Australia have excellent long-term survival, which is unchanged since 1983. SPMs are uncommon following treatment for childhood renal cancer but carry a poor prognosis. Relapse carries a similarly poor prognosis to SPM but is more common. These data are comparable to registry outcomes in similarly developed nations.

Comprehensive analysis of long non‑coding RNA using an associated competitive endogenous RNA network in Wilms tumor

Wilms tumor (WT) is the most common malignant renal neoplasm in children; however, the underlying molecular mechanisms are not well understood. According to the competing endogenous RNA (ceRNA) theory, long non-coding RNAs (lncRNAs) can regulate the expression of target genes by adsorbing microRNAs (miRNAs/miRs). However, the role of lncRNAs in WT has not been fully elucidated. The aim of the present study was to construct a ceRNA network to identify the potential lncRNAs involved in WT. The expression profiles of lncRNAs, miRNAs and mRNAs in 120 WT and six normal tissues were obtained from the Therapeutically Applicable Research to Generate Effective Treatments database. A total of 442 lncRNAs, 214 miRNAs and 4,912 mRNAs were identified as differentially expressed in WT and were enriched in 472 Gene Ontology terms (355 biological processes, 89 cellular components and 29 molecular functions) and 18 Kyoto Encyclopedia of Genes and Genomes pathways. A lncRNA-miRNA-mRNA ceRNA network of WT consisting of with 32 lncRNAs, 14 miRNAs and 158 mRNAs was constructed, based on the bioinformatics analysis of the miR target prediction database and the miRNAcode, miRTarBase and TargetScan databases. Subsequently, three lncRNAs, three miRNAs and 17 mRNAs, which had a significant effect on the overall survival rate of patients with WT, were identified based on the survival analysis. The three lncRNAs were also differentially expressed in the late and early stages of WT and were validated using the GSE66405 dataset obtained from the Gene Expression Omnibus database. In conclusion, the present study generated a specific lncRNA-related ceRNA network of WT, which may provide a novel perspective on the molecular mechanisms underlying the progression and prognosis of the disease.

The Dutch LATER physical outcomes set for self-reported data in survivors of childhood cancer

Purposes

Studies investigating self-reported long-term morbidity in childhood cancer survivors (CCS) are using heterogeneous outcome definitions, which compromises comparability and include (un)treated asymptomatic and symptomatic outcomes. We generated a Dutch LATER core set of clinically relevant physical outcomes, based on self-reported data. Clinically relevant outcomes were defined as outcomes associated with clinical symptoms or requiring medical treatment.

Methods

First, we generated a draft outcome set based on existing questionnaires embedded in the Childhood Cancer Survivor Study, British Childhood Cancer Survivor Study, and Dutch LATER study. We added specific outcomes reported by survivors in the Dutch LATER questionnaire. Second, we selected a list of clinical relevant outcomes by agreement among a Dutch LATER experts team. Third, we compared the proposed clinically relevant outcomes to the severity grading of the Common Terminology Criteria for Adverse Events (CTCAE).

Results

A core set of 74 self-reported long-term clinically relevant physical morbidity outcomes was established. Comparison to the CTCAE showed that 36% of these clinically relevant outcomes were missing in the CTCAE.

Implications for Cancer Survivors

This proposed core outcome set of clinical relevant outcomes for self-reported data will be used to investigate the self-reported morbidity in the Dutch LATER study. Furthermore, this Dutch LATER outcome set can be used as a starting point for international harmonization for long-term outcomes in survivors of childhood cancer.

Electronic supplementary material

The online version of this article (10.1007/s11764-020-00880-0) contains supplementary material, which is available to authorized users.

Kidney-sparing whole abdominal irradiation in Wilms tumor: Potential advantages of VMAT technique

PURPOSE

To present a preliminary clinical experience and a dosimetric comparison of kidney-sparing volumetric modulated arc therapy (VMAT) with three-dimensional conformal radiotherapy (3D-CRT) for whole abdominal irradiation (WAI), in the setting of Wilms tumor (WT) treatment.

MATERIALS AND METHODS

From a total of 20 consecutive WT cases treated with adjuvant irradiation, seven were submitted to WAI with VMAT. Renal function and survival rates were evaluated, and, for comparison purposes, similar VMAT and 3D-CRT treatment plans were performed for WAI patients, and differences were dosimetrically evaluated regarding doses to the remaining kidney and other organs at risk and the planning target volume (PTV).

RESULTS

After a median follow-up time of 40.8 months (35.3-52.2), no acute significant intestinal toxicity was observed, and median creatinine clearance was 110.1 and 103.3 mL/min/1.73 m², respectively, before treatment and at last follow-up for WAI patients (P = 0.128). For comparative plans, maximum and median doses were lower for the remaining kidney with VMAT than with 3D-CRT. VMAT was associated with better PTV coverage as compared with 3D-CRT, with superior results for all the evaluated parameters (D95, D2, V100%, V98%, V95%; P = 0.018).

CONCLUSION

The use of VMAT technique is associated with lower radiation doses to the remaining kidney and better coverage to the PTV than 3D-CRT technique for WAI, with preliminary clinical experience showing a favorable toxicity profile. Long-term results from prospective studies might prove the ability of VMAT to spare renal function in the setting of WT treatment.

Outcome analysis of stage I epithelial-predominant favorable-histology Wilms tumors: A report from Children's Oncology Group study AREN03B2

BACKGROUND

Stage I epithelial-predominant favorable-histology Wilms tumors (EFHWTs) have long been suspected to have an excellent outcome. This study investigates the clinical and pathologic features of patients with stage I EFHWTs to better evaluate the potential for a reduction of chemotherapy and its associated toxicity.

METHODS

All patients registered in the Children's Oncology Group (COG) AREN03B2 study between 2006 and 2017 with stage I EFHWTs were identified. EFHWTs were defined as tumors with at least 66% epithelial differentiation, regardless of the degree of differentiation. Clinical information was abstracted from COG records. Event-free survival (EFS) and overall survival (OS) were calculated and compared between groups based on age and therapy.

RESULTS

The 4-year EFS rate was 96.2% (95% confidence interval, 92%-100%), and the OS rate was 100%; EFS and OS did not statistically significantly differ with the age at diagnosis (<48 vs ≥48 months; P = .37) or treatment (EE4A vs observation only; P = .55). Six events were reported. Three patients developed contralateral tumors and did not otherwise relapse; none of these had nephrogenic rests or a recognized predisposition syndrome. Three patients developed metastatic recurrence; all 3 had received EE4A as their primary therapy after nephrectomy.

CONCLUSIONS

These findings demonstrate an excellent outcome for stage I EFHWTs with >95% EFS and OS. These data support the utility of investigating the treatment of stage I EFHWTs with observation alone after nephrectomy.

Progress toward liquid biopsies in pediatric solid tumors

Pediatric solid tumors have long been known to shed tumor cells, DNA, RNA, and proteins into the blood. Recent technological advances have allowed for improved capture and analysis of these typically scant circulating materials. Efforts are ongoing to develop "liquid biopsy" assays as minimally invasive tools to address diagnostic, prognostic, and disease monitoring needs in childhood cancer care. Applying these highly sensitive technologies to serial liquid biopsies is expected to advance understanding of tumor biology, heterogeneity, and evolution over the course of therapy, thus opening new avenues for personalized therapy. In this review, we outline the latest technologies available for liquid biopsies and describe the methods, pitfalls, and benefits of the assays that are being developed for children with extracranial solid tumors. We discuss what has been learned in several of the most common pediatric solid tumors including neuroblastoma, sarcoma, Wilms tumor, and hepatoblastoma and highlight promising future directions for the field.

Novel therapy for pediatric and adolescent kidney cancer

Pediatric and adolescent renal tumors account for approximately 7% of all new cancer diagnoses in the USA each year. The prognosis and treatment are varied based on factors including the underlying histology and tumor stage, with survival rates ranging from greater than 90% in favorable histology Wilms tumor to almost universally fatal in other disease types, including those patients with advanced stage malignant rhabdoid tumor and renal medullary carcinoma. In recent years, our understanding of the underlying genetic drivers of the different types of pediatric kidney cancer has dramatically increased, opening the door to utilization of new targeted biologic agents alone or in combination with conventional chemotherapy to improve outcomes. Several ongoing clinical trials are investigating the use of a variety of targeted agents in pediatric patients with underlying genetic aberrations. In this manuscript, the underlying biology and early phase clinical trials relevant to pediatric renal cancers are reviewed.

Prohibitin is a prognostic marker and therapeutic target to block chemotherapy resistance in Wilms' tumor

Wilms' tumor is the most common type of childhood kidney cancer. To improve risk stratification and identify novel therapeutic targets for patients with Wilms' tumor, we used high-resolution mass spectrometry proteomics to identify urine tumor markers associated with Wilms' tumor relapse. We determined the urine proteomes at diagnosis of 49 patients with Wilms' tumor, non-Wilms' tumor renal tumors, and age-matched controls, leading to the quantitation of 6520 urine proteins. Supervised analysis revealed specific urine markers of renal rhabdoid tumors, kidney clear cell sarcomas, renal cell carcinomas as well as those detected in patients with cured and relapsed Wilms' tumor. In particular, urine prohibitin was significantly elevated at diagnosis in patients with relapsed as compared with cured Wilms' tumor. In a validation cohort of 139 patients, a specific urine prohibitin ELISA demonstrated that prohibitin concentrations greater than 998 ng/mL at diagnosis were significantly associated with ultimate Wilms' tumor relapse. Immunohistochemical analysis revealed that prohibitin was highly expressed in primary Wilms' tumor specimens and associated with disease stage. Using functional genetic experiments, we found that prohibitin was required for the growth and survival of Wilms' tumor cells. Overexpression of prohibitin was sufficient to block intrinsic mitochondrial apoptosis and to cause resistance to diverse chemotherapy drugs, at least in part by dysregulating factors that control apoptotic cytochrome c release from mitochondrial cristae. Thus, urine prohibitin may improve therapy stratification, noninvasive monitoring of treatment response, and early disease detection. In addition, therapeutic targeting of chemotherapy resistance induced by prohibitin dysregulation may offer improved therapies for patients with Wilms' and other relapsed or refractory tumors.

Customized approach for upfront or delayed resection using radiological criteria in unilateral, nonmetastatic pediatric renal tumors: A prospective study

BACKGROUND

The availability of robust, equivalent data regarding outcomes for upfront or delayed surgery for renal tumors in children leads to a dilemma in selecting the initial treatment. Imaging criteria associated with the probability of rupture or incomplete resection may provide a more objective assessment for customization for the timing of surgery.

PROCEDURE

Eighty-three children with unilateral, nonmetastatic renal tumors were enrolled between January 2012 and April 2018. Upfront nephrectomy was performed in the absence or delayed surgery (after a biopsy and chemotherapy) in the presence of one or more imaging-based high-risk features, including perinephric spread or adjacent organ infiltration, tumors crossing the midline, intravascular thrombus, and extensive adenopathy. Post hoc analysis for interobserver concordance for high-risk imaging features was also performed.

RESULTS

The upfront surgery group (19) had predominantly stage I or II diseases (89%) and the histological types were Wilms (13), non-Wilms (5) renal tumor, and an inflammatory lesion. The delayed surgery group had 60% with stage I or II diseases and the histological types were Wilms (60) and non-Wilms (4) tumor. In addition, high-risk pathology was identified in nine patients. Overall, 27 patients with Wilms tumors required radiotherapy and anthracycline because of stage III disease, including one in the immediate surgery group. The event-free and overall survival (OS) at a median follow-up of 39 months for Wilms tumor are 88% (95% confidence interval [CI]: 78.5-94.9%) and 89% (95% CI: 81.4-96.6%), 85.1% (95% CI: 73.8-93.4%) and 86.5% (95% CI: 77.4-95.8%) for the delayed, and 100% event-free survival as well as OS (P = .1) in the upfront surgery group.

CONCLUSION

A customized approach pivoted on image-based high-risk features facilitates identification of patients with early-stage renal tumor when the timing of surgery is tailored. Moreover, non-Wilms tumor and high-risk pathology are also identified.

Adaptations to a Generalized Radiation Dose Reconstruction Methodology for Use in Epidemiologic Studies: An Update from the MD Anderson Late Effect Group

Epidemiologic studies that include patients who underwent radiation therapy for the treatment of cancer aim to quantify the relationship between radiotherapy and the risk of subsequent late effects. Because of the long follow-up period required to observe late effects, these studies are conducted retrospectively. The studies routinely include patients treated across numerous institutions using a wide range of technologies and represent treatments over several decades. As a result, determining the dose throughout the patient's body is uniquely challenging. Therefore, estimating doses throughout the patient's body for epidemiologic studies requires special methodologies that are generally applied to a wide range of radiotherapy techniques. Over ten years ago, the MD Anderson Late Effects Group described various dose reconstruction methods for therapeutic and diagnostic radiation exposure for epidemiologic studies. Here we provide an update to the most widely used dose reconstruction methodology for epidemiologic studies, analytical model calculations combined with a 3D age-specific computational phantom. In particular, we describe the various adaptations (and enhancements) of that methodology, as well as how they have been used in radiation epidemiology studies and may be used in future studies.

Neurocognitive outcomes in long-term survivors of Wilms tumor: a report from the St. Jude Lifetime Cohort

PURPOSE

To examine prevalence and predictors of neurocognitive outcomes, social attainment, emotional distress, and health-related quality of life (HRQOL) in long-term survivors of pediatric Wilms tumor (WT).

METHODS

One hundred fifty-eight WT survivors (59% female; mean [SD] age 33 [9.1] years; time since diagnosis 29 [9.1] years) and 354 community controls (55.6% female; 35 [10.2] years) completed comprehensive neuropsychological testing and physical examination, including echocardiography/electrocardiography, pulmonary function tests, and endocrine evaluation. Self-report of emotional distress, HRQOL, and social attainment were collected. Impairment was defined in relation to both controls and normative data. Generalized linear models were developed to examine impact of treatment and chronic health conditions on outcomes.

RESULTS

WT survivors performed poorer than norms and controls in 6 of 16 cognitive variables and 1 of 8 HRQOL variables, with scores ranging from - 0.64 (mathematics) to - 0.21 (verbal fluency) standard deviations below expectations. Compared to controls, WT survivors were less likely to graduate college (odds ratio 2.23, 95% confidence interval 1.46-3.41) and had more moderate to severe neurologic conditions (18.4% vs 8.2%, p < 0.001), which were associated with poor memory (β = - 0.90, p < 0.001), attention (β = - 1.02, p < 0.001), and HRQOL general health (β = - 0.80, p = 0.0015). Treatment variables and cardiopulmonary morbidity (higher in survivors) were not associated with outcomes.

CONCLUSIONS

Survivors of WT demonstrate impairment in neurocognitive function and have lower social attainment during adulthood, with poorer neurocognitive function associated with neurologic morbidity.

IMPLICATIONS FOR CANCER SURVIVORS

Survivors of WT should be offered neurocognitive evaluations and rehabilitation. Neurologic conditions should be routinely assessed, and appropriate support offered to reduce risk for functional limitations.

Early and late adverse renal effects after potentially nephrotoxic treatment for childhood cancer

BACKGROUND

Improvements in diagnostics and treatment for paediatric malignancies resulted in a major increase in survival. However, childhood cancer survivors (CCS) are at risk of developing adverse effects caused by multimodal treatment for their malignancy. Nephrotoxicity is a known side effect of several treatments, including cisplatin, carboplatin, ifosfamide, radiotherapy and nephrectomy, and can cause glomerular filtration rate (GFR) impairment, proteinuria, tubulopathy, and hypertension. Evidence about the long-term effects of these treatments on renal function remains inconclusive. It is important to know the risk of, and risk factors for, early and late adverse renal effects, so that ultimately treatment and screening protocols can be adjusted. This review is an update of a previously published Cochrane Review.

OBJECTIVES

To evaluate existing evidence on the effects of potentially nephrotoxic treatment modalities on the prevalence of renal dysfunction in survivors treated for childhood cancer with a median or mean survival of at least one year after cessation of treatment, where possible in comparison with the general population or CCS treated without potentially nephrotoxic treatment. In addition, to evaluate evidence on associated risk factors, such as follow-up duration, age at time of diagnosis and treatment combinations, as well as the effect of doses.

SEARCH METHODS

On 31 March 2017 we searched the following electronic databases: CENTRAL, MEDLINE and Embase. In addition, we screened reference lists of relevant studies and we searched the congress proceedings of the International Society of Pediatric Oncology (SIOP) and The American Society of Pediatric Hematology/Oncology (ASPHO) from 2010 to 2016/2017.

SELECTION CRITERIA

Except for case reports, case series and studies including fewer than 20 participants, we included studies with all study designs that reported on renal function (one year or longer after cessation of treatment), in CCS treated before the age of 21 years with cisplatin, carboplatin, ifosfamide, radiation involving the kidney region, a nephrectomy, or a combination of two or more of these treatments. When not all treatment modalities were described or the study group of interest was unclear, a study was not eligible for the evaluation of prevalence. We still included it for the assessment of risk factors if it had performed a multivariable analysis.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, 'Risk of bias' assessment and data extraction using standardised data collection forms. We performed analyses according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

Apart from the remaining 37 studies included from the original review, the search resulted in the inclusion of 24 new studies. In total, we included 61 studies; 46 for prevalence, six for both prevalence and risk factors, and nine not meeting the inclusion criteria, but assessing risk factors. The 52 studies evaluating the prevalence of renal dysfunction included 13,327 participants of interest, of whom at least 4499 underwent renal function testing. The prevalence of adverse renal effects ranged from 0% to 84%. This variation may be due to diversity of included malignancies, received treatments, reported outcome measures, follow-up duration and the methodological quality of available evidence.Seven out of 52 studies, including 244 participants, reported the prevalence of chronic kidney disease, which ranged from 2.4% to 32%.Of these 52 studies, 36 studied a decreased (estimated) GFR, including at least 432 CCS, and found it was present in 0% to 73.7% of participants. One eligible study reported an increased risk of glomerular dysfunction after concomitant treatment with aminoglycosides and vancomycin in CCS receiving total body irradiation (TBI). Four non-eligible studies assessing a total cohort of CCS, found nephrectomy and (high-dose (HD)) ifosfamide as risk factors for decreased GFR. The majority also reported cisplatin as a risk factor. In addition, two non-eligible studies showed an association of a longer follow-up period with glomerular dysfunction.Twenty-two out of 52 studies, including 851 participants, studied proteinuria, which was present in 3.5% to 84% of participants. Risk factors, analysed by three non-eligible studies, included HD cisplatin, (HD) ifosfamide, TBI, and a combination of nephrectomy and abdominal radiotherapy. However, studies were contradictory and incomparable.Eleven out of 52 studies assessed hypophosphataemia or tubular phosphate reabsorption (TPR), or both. Prevalence ranged between 0% and 36.8% for hypophosphataemia in 287 participants, and from 0% to 62.5% for impaired TPR in 246 participants. One non-eligible study investigated risk factors for hypophosphataemia, but could not find any association.Four out of 52 studies, including 128 CCS, assessed the prevalence of hypomagnesaemia, which ranged between 13.2% and 28.6%. Both non-eligible studies investigating risk factors identified cisplatin as a risk factor. Carboplatin, nephrectomy and follow-up time were other reported risk factors.The prevalence of hypertension ranged from 0% to 50% in 2464 participants (30/52 studies). Risk factors reported by one eligible study were older age at screening and abdominal radiotherapy. A non-eligible study also found long follow-up time as risk factor. Three non-eligible studies showed that a higher body mass index increased the risk of hypertension. Treatment-related risk factors were abdominal radiotherapy and TBI, but studies were inconsistent.Because of the profound heterogeneity of the studies, it was not possible to perform meta-analyses. Risk of bias was present in all studies.

AUTHORS' CONCLUSIONS

The prevalence of adverse renal effects after treatment with cisplatin, carboplatin, ifosfamide, radiation therapy involving the kidney region, nephrectomy, or any combination of these, ranged from 0% to 84% depending on the study population, received treatment combination, reported outcome measure, follow-up duration and methodological quality. With currently available evidence, it was not possible to draw solid conclusions regarding the prevalence of, and treatment-related risk factors for, specific adverse renal effects. Future studies should focus on adequate study designs and reporting, including large prospective cohort studies with adequate control groups when possible. In addition, these studies should deploy multivariable risk factor analyses to correct for possible confounding. Next to research concerning known nephrotoxic therapies, exploring nephrotoxicity after new therapeutic agents is advised for future studies. Until more evidence becomes available, CCS should preferably be enrolled into long-term follow-up programmes to monitor their renal function and blood pressure.

Update on Wilms tumor

This article reviews of the current evidence-based treatment standards for children with Wilms tumor. In this article, a summary of recently completed clinical trials by the Children's Oncology Group is provided, the current diagnostic evaluation and surgical standards are discussed, and the surgical impact on current risk stratification for patients with Wilms tumor is highlighted. LEVEL OF EVIDENCE: This is a review article of previously published and referenced LEVEL 1 studies, but also includes expert opinion LEVEL V, represented by the American Pediatric Surgical Association Cancer Committee.

Combined Genetic and Chromosomal Characterization of Wilms Tumors Identifies Chromosome 12 Gain as a Potential New Marker Predicting a Favorable Outcome

To identify prognostic factors, array CGH (aCGH) patterns and mutations in WT1 and 9 other genes were analyzed in 128 unilateral Wilms tumors (WTs). Twenty patients had no aCGH aberrations, and 31 had WT1 alterations [silent and WT1 types: relapse-free survival (RFS), 95% and 83%, respectively]. Seventy-seven patients had aCGH changes without WT1 alterations (nonsilent/non-WT1 type) and were subtyped into those with or without +12, 11q-, 16q-, or HACE1 loss. RFS was better for those with than those without +12 (P = .010) and worse for those with than those without 11q-, 16q-, or HACE1 loss (P = .001, .025, or 1.2E-04, respectively). Silent and WT1 type and 8 subtype tumors were integrated and classified into 3 risk groups: low risk for the silent type and +12 subgroup; high risk for the no +12 plus 11q-, 16q-, or HACE1 loss subgroup; intermediate risk for the WT1 type and no +12 plus no 11q-, 16q-, or HACE1 loss subgroup. Among the 27 WTs examined, the expression of 146 genes on chromosome 12 was stronger in +12 tumors than in no +12 tumors, while that of 10 genes on 16q was weaker in 16q- tumors than in no 16q- tumors. Overexpression in 75 out of 146 upregulated genes and underexpression in 7 out of 10 downregulated genes correlated with better and worse overall survival, respectively, based on the public database. +12 was identified as a potential new marker predicting a favorable outcome, and chromosome abnormalities may be related to altered gene expression associated with these abnormalities.

Lymph node imaging of pediatric renal and suprarenal malignancies

Pediatric renal and suprarenal cancers are relatively rare malignancies, but are not without significant consequence to both the patient and caretakers. These tumors are often found incidentally and present as large abdominal masses. Standard of care management involves surgical excision of the mass, but contemporary treatment guidelines advocate for use of neoadjuvant or adjuvant chemotherapy for advanced stage disease, such as those cases with lymph node involvement (LNI). However, LNI detection is based primarily on surgical pathology and performing extended lymph node dissection can add significant morbidity to a surgical case. In this review, we focus on the use and performance of imaging modalities to detect LNI in Wilms’ tumor (WT), neuroblastoma, and pediatric renal cell carcinoma (RCC). We report on how imaging impacts management of these cases and the clinical implications of LNI. A literature search was conducted for studies published on imaging-based detection of LNI in pediatric renal and suprarenal cancers. Further review focused on surgical and medical management of those cases with suspected LNI. Current imaging protocols assisting in diagnosis and staging of pediatric renal and suprarenal cancers are generally limited to abdominal ultrasound and cross-sectional imaging, mainly computed tomography (CT). Recent research has investigated the role of more advance modalities, such as magnetic resonance imaging (MRI) and positron emission tomography (PET), in the management of these malignancies. Special consideration must be made for pediatric patients who are more vulnerable to ionizing radiation and have characteristic imaging features different from adult controls. Management of pediatric renal and suprarenal cancers is influenced by LNI, but the rarity of these conditions has limited the volume of clinical research regarding imaging-based staging. As such, standardized criteria for LNI on imaging are lacking. Nevertheless, advanced imaging modalities are being investigated and potentially represent more accurate and safer options.

Surviving childhood cancer: a systematic review of studies on risk and determinants of adverse socioeconomic outcomes

Substantial improvements in childhood cancer survival have resulted in a steadily increasing population of childhood cancer survivors. Whereas somatic late effects have been assessed in many studies, less is known about the impact of childhood cancer on socioeconomic outcomes in survivors. The aim of this article was to evaluate and summarise the evidence on the socioeconomic conditions of childhood cancer survivors and to identify survivors at particular risk of adverse socioeconomic outcomes. An extensive literature search of three electronic databases was conducted. Of 419 articles identified, 52 met the inclusion criteria. All the selected articles were appraised for quality, and findings were summarised in a narrative synthesis. Childhood cancer survivors were at higher risk of adverse socioeconomic outcomes with regard to educational achievement, income and social security benefits than the general population or a sibling comparison group. The risks for unemployment and a lower occupational position were significantly increased only for survivors of a central nervous system tumour. Notably, survivors of central nervous system tumours, survivors treated with cranial radiotherapy and those diagnosed at younger age independent of cancer type were determinants of particular adverse socioeconomic outcomes. Given the increasing population of childhood cancer survivors, targeted follow-up interventions and support strategies addressing not only the somatic and psychiatric late effects but also the socioeconomic difficulties that some childhood cancer survivors face is of high importance to reduce social inequity, and ensure a high quality of life after childhood cancer.

Cardiac-Sparing Whole Lung IMRT in Patients With Pediatric Tumors and Lung Metastasis: Final Report of a Prospective Multicenter Clinical Trial

PURPOSE

A prospective clinical trial was conducted for patients undergoing cardiac sparing (CS) whole lung irradiation (WLI) using intensity modulated radiation therapy (IMRT). The 3 trial aims were (1) to demonstrate the feasibility of CS IMRT with real-time central quality control; (2) to determine the dosimetric advantages of WLI using IMRT compared with standard anteroposterior (AP) techniques; and (3) to determine acute tolerance and short-term efficacy after a protocol-mandated minimum 2-year follow-up for all patients.

METHODS AND MATERIALS

All patients underwent a 3-dimensional chest computed tomography scan and a contrast-enhanced 4-dimensional (4D) gated chest computed tomography scan using a standard gating device. The clinical target volume was the entire bilateral 3-dimensional lung volume, and the internal target volume was the 4D minimum intensity projection of both lungs. The internal target volume was expanded by 1 cm to get the planning target volume. All target volumes, cardiac contours, and treatment plans were centrally reviewed before treatment. The different cardiac volumes receiving percentages of prescribed radiation therapy (RT) doses on AP and IMRT WLI plans were estimated and compared.

RESULTS

The target 20 patients were accrued in 2 years. Median RT dose was 15 Gy. Real-time central quality assurance review and plan preapproval were obtained for all patients. WLI using IMRT was feasible in all patients. Compared with standard AP WLI, CS IMRT resulted in a statistically significant reduction in radiation doses to the whole heart, atria, ventricles, and coronaries. One child developed cardiac dysfunction and pulmonary restrictive disease 5.5 years after CS IMRT (15 Gy) and doxorubicin (375 mg/m²). The 2- and 3-year lung metastasis progression-free survival was 65% and 52%, respectively.

CONCLUSIONS

We have demonstrated the feasibility of WLI using CS IMRT and confirmed the previously reported advantages of IMRT, including superior cardiac protection and superior dose coverage of 4D lung volumes. Further studies are required to establish the efficacy and safety of this irradiation technique.

Cardiac-Sparing Whole Lung Intensity Modulated Radiation Therapy in Children With Wilms Tumor: Final Report on Technique and Abdominal Field Matching to Maximize Normal Tissue Protection

PURPOSE

Cardiac-sparing whole lung intensity modulated radiation therapy (WL IMRT) has been shown to improve cardiac protection and lung volume dose coverage compared with standard anteroposterior techniques. This dosimetry study had 2 aims: To determine the dosimetric advantages of a modified WL IMRT (M-WL IMRT) technique, designed to reduce radiation exposure to the thyroid gland and breast tissues, compared with standard WL IMRT (S-WL IMRT) and to determine the dosimetric advantages of M-WL IMRT and dosimetrically matched abdomen and flank radiation therapy (RT) fields designed to reduce normal tissue exposure compared with standard field matching techniques.

METHODS AND MATERIALS

Computed tomography scans of the chest and abdomen that were obtained during computed tomography simulation of 10 female children were used. For Aim 1, for S-WL IMRT, the planning target volume (PTV) was obtained with a 1-cm expansion of the 4-dimensional lung volume (internal target volume). For M-WL IMRT, the PTV was reduced around the breast and thyroid gland to facilitate thyroid and breast sparing. For Aim 2, standard matching techniques for 3-dimensional anterior/posterior-posterior/anteriorwhole lung and abdominal RT fields were compared with a new dosimetric matching technique for WL IMRT and abdomen and flank fields. For both aims, the dose coverage of the lungs and radiation exposure to normal tissues (heart, thyroid, breasts) were statistically compared.

RESULTS

Compared with S-WL IMRT, the M-WL IMRT technique provided similar lung PTV dose coverage and a significantly superior reduction in mean breast and thyroid doses, without compromising cardiac protection. The M-WL IMRT technique combined with a dosimetrically matched abdomen and flank fields showed significantly superior normal tissue protection compared with standard matched anterior/posterior-posterior/anteriorlung and abdomen and flank RT fields.

CONCLUSIONS

This study has shown that the M-WL IMRT technique can reduce radiation exposure to the thyroid gland and breast tissue without compromising cardiac protection and 4-dimensional lung volume dose coverage. This report also describes a new dosimetric matching technique between WL IMRT and abdomen and flank fields that will improve normal tissue sparing compared with standard techniques.

Laparoscopic nephrectomy for Wilms' tumor: Can we expand on the current SIOP criteria?

INTRODUCTION

Wilms' tumor now has a good overall prognosis with open radical nephrectomy having been the mainstay of surgical treatment. Recently laparoscopic nephrectomy (LN) has been growing in popularity. The aim of our study was to review our indications and outcomes for laparoscopic resections for Wilms' tumor and compare indications with International Society of Paediatric Oncology (SIOP) criteria for LN.

MATERIAL AND METHODS

Patient demographics, preoperative management, surgical data, respect of SIOP criteria, complications, disease outcome, and follow-up were recorded on consecutive children who underwent nephrectomy for Wilms' tumor.

RESULTS AND DISCUSSION

Fifty-four consecutive children with Wilms' tumor underwent a nephrectomy; 20 had a LN (Table). Nine of 20 (45%) patients who had LN did not meet SIOP criteria for LN. No patients had an intraoperative tumor rupture and one patient had positive margins because of preoperative rupture. There were two conversions: one caused by difficulty accessing the renal hilum and the other caused by difficulty maintaining oxygen saturations. There was one local recurrence.

CONCLUSION

SIOP criteria are conservative and safe. Indications can be extended for teams experienced in surgical oncology and laparoscopy after agreement at a multidisciplinary meeting (MDM).

Treatment of Stage IV Favorable Histology Wilms Tumor With Lung Metastases: A Report From the Children's Oncology Group AREN0533 Study

Purpose The National Wilms Tumor Study (NWTS) treatment of favorable histology Wilms tumor with lung metastases was vincristine/dactinomycin/doxorubicin (DD4A) and lung radiation therapy (RT). The AREN0533 study applied a new risk stratification and treatment strategy to improve event-free survival (EFS) while reducing exposure to lung RT. Methods Patients with favorable histology Wilms tumor and isolated lung metastases showing complete lung nodule response (CR) after 6 weeks of DD4A continued receiving chemotherapy without lung RT. Patients with incomplete response (IR) or loss of heterozygosity at chromosomes 1p/16q received lung RT and four cycles of cyclophosphamide/etoposide in addition to DD4A drugs (Regimen M). AREN0533 was designed to preserve a 4-year EFS of 85% for lung nodule CR and improve 4-year EFS from 75% to 85% for lung nodule IR. Results Among 292 assessable patients, 133 had CR and 159 had IR. For patients with CR, 4-year EFS and overall survival (OS) estimates were 79.5% (95% CI, 71.2% to 87.8%) and 96.1% (95% CI, 92.1% to 100%), respectively. Expected versus observed event rates were 15% and 20.2% ( P = .052), respectively. For patients with IR, 4-year EFS and OS estimates were 88.5% (95% CI, 81.8% to 95.3%) and 95.4% (95% CI, 90.9% to 99.8%), respectively. Expected versus observed event rates were 25% and 12.2% ( P < .001), respectively. Overall, 4-year EFS and OS were 85.4% (95% CI, 80.5% to 90.2%) and 95.6% (95% CI, 92.8% to 98.4%) compared with 72.5% (95% CI, 66.9% to 78.1%; P < .001) and 84.0% (95% CI, 79.4% to 88.6%; P < .001), respectively, in the predecessor NWTS-5 study. Conclusion Excellent OS was achieved after omission of primary lung RT in patients with lung nodule CR, although there were more events than expected. EFS was significantly improved, with excellent OS, in patients with lung nodule IR using four cycles of cyclophosphamide/etoposide in addition to DD4A drugs. The overall AREN0533 treatment strategy yielded EFS and OS estimates that were superior to previous studies.

Urological issues arising after treatment of pediatric malignancies

N/A

Partial Nephrectomy for Nephroblastoma: A National Cancer Data Base Review

Standard of care for unilateral nephroblastoma includes total nephrectomy (TN) with nodal sampling. We sought to compare the outcomes of TN and partial nephrectomy (PN). We performed a retrospective cohort study of TN and PN for nephroblastoma using the National Cancer Data Base. The outcomes included nodal sampling frequency, margin status, and survival. Categorical and continuous data were evaluated with χ2 and t tests, respectively ( P < 0.05). Generalized linear models evaluated nodal sampling and margin status. Cox regression compared survival. In total, 235 patients underwent PN and 3572 had TN. TN patients were 50 per cent more likely to undergo nodal sampling (RR: 1.47, 95% CI 1.30–1.66). There was no difference in margin status (RR: 0.91, 95% CI 0.65–1.28) or overall survival (HR 1.57; 95% CI 0.78–3.19). This study reports the largest review of patients with PN for unilateral nephroblastoma. PN patients had less nodal sampling but similar margin involvement and overall survival.

miR-423 rs6505162 C>A polymorphism contributes to decreased Wilms tumor risk

Wilms tumor (WT) is the most prevalent urologic malignancy in childhood. Nonetheless, the genetic factors underlying WT remain largely unknown. The miR-423 rs6505162 C>A polymorphism is associated with the susceptibility to numerous cancers; however, no investigations have been conducted on its association with WT. To evaluate the correlation between the miR-423 rs6505162 C>A polymorphism and WT risk in Chinese children, we genotyped this polymorphism using the Taqman method in 145 cases and 531 cancer-free controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the strength of the association. The results showed that the rs6505162 CA genotype was associated with decreased susceptibility to WT (CA versus CC: adjusted OR=0.65, 95% CI=0.42-0.99, P=0.047). In the stratified analysis, we found that CA/AA genotypes conferred a significantly decreased overall risk of WT in children younger than 18 months (adjusted OR=0.30, 95% CI=0.14-0.63, P=0.002) and those with clinical stage I+II WT (adjusted OR=0.42, 95% CI=0.20-0.85, P=0.017) when compared with CC genotype. In summary, the miR-423 rs6505162 C>A polymorphism may negatively modify WT susceptibility in Chinese children. Our findings should be validated in larger studies involving other ethnicities.

The correlation between LIN28B gene potentially functional variants and Wilms tumor susceptibility in Chinese children

BACKGROUND

Wilms tumor (WT) is the most common urologic cancer in children. However, genetic bases underlying WT remain largely unknown. Previous studies indicated that Lin28 homolog B (LIN28B) level is significantly elevated in some WTs. Enforced expression of Lin28b during kidney development could induce WT. Genetic variations in the LIN28B gene may be related to WT susceptibility.

METHOD

In this study, we aimed to assess the association between LIN28B gene polymorphisms and WT susceptibility in Chinese children. Four potentially functional polymorphisms in the LIN28B gene (rs314276 C>A, rs221634 A>T, rs221635 T>C and rs9404590 T>G) were genotyped in 145 cases and 531 cancer-free controls, using Taqman method. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the strength of the associations.

RESULTS

Our results showed that the rs314276 CA genotype was associated with a decreased WT risk (CA vs CC: adjusted OR=0.65, 95% CI=0.43-0.98, P=.042). Moreover, we found that carriers of the 1-3 risk genotypes had a significantly increased WT risk when compared to the non-carriers (adjusted OR=1.51, 95% CI=1.03-2.20, P=.035). The association with risk genotypes was more predominant in children 18 month old or younger and in females.

CONCLUSION

In summary, these results indicated that the LIN28B gene rs314276 C>A polymorphism alone and three combined polymorphisms may be able to modify WT susceptibility in Southern Chinese children. Our findings call for further validation in large studies with different ethnicities involved.

Outcome and Prognostic Factors in Stage III Favorable-Histology Wilms Tumor: A Report From the Children's Oncology Group Study AREN0532

Background The National Wilms Tumor Study (NWTS) approach to treating stage III favorable-histology Wilms tumor (FHWT) is Regimen DD4A (vincristine, dactinomycin, and doxorubicin) and radiation therapy. Further risk stratification is required to improve outcomes and reduce late effects. We evaluated clinical and biologic variables for patients with stage III FHWT without combined loss of heterozygosity (LOH) at chromosomes 1p and 16q treated in the Children's Oncology Group protocol AREN0532. Methods From October 2006 to August 2013, 588 prospectively treated, centrally reviewed patients with stage III FHWT were treated with Regimen DD4A and radiation therapy. Tumor LOH at 1p and 16q was determined by microsatellite analysis. Ineligible patients (n = 5) and those with combined LOH 1p/16q (n = 40) were excluded. Results A total of 535 patients with stage III disease were studied. Median follow-up was 5.2 years (range, 0.2 to 9.5). Four-year event-free survival (EFS) and overall survival estimates were 88% (95% CI, 85% to 91%) and 97% (95% CI, 95% to 99%), respectively. A total of 58 of 66 relapses occurred in the first 2 years, predominantly pulmonary (n = 36). Eighteen patients died, 14 secondary to disease. A better EFS was associated with negative lymph node status ( P < .01) and absence of LOH 1p or 16q ( P < .01), but not with gross residual disease or peritoneal implants. In contrast, the 4-year EFS was only 74% in patients with combined positive lymph node status and LOH 1p or 16q. A total of 123 patients (23%) had delayed nephrectomy. Submitted delayed nephrectomy histology showed anaplasia (n = 8; excluded from survival analysis); low risk/completely necrotic (n = 7; zero relapses), intermediate risk (n = 63; six relapses), and high-risk/blastemal type (n=7; five relapses). Conclusion Most patients with stage III FHWT had good EFS/overall survival with DD4A and radiation therapy. Combined lymph node and LOH status was highly predictive of EFS and should be considered as a potential prognostic marker for future trials.

Prevalence of cardiovascular late sequelae in long-term survivors of childhood cancer: A systematic review and meta-analysis

BACKGROUND

Cardiovascular diseases are well-known late effects of childhood cancer and research on these late effects is a highly important emerging field. We conducted a systematic review with a meta-analysis to give an overview of the current evidence and the prevalence of late cardiovascular events.

PROCEDURE

We included publications in which the study populations were children and adolescents who survived cancer. Outcome was defined as all cardiovascular clinical and subclinical endpoints or diagnoses appearing at least one year after cancer diagnosis. A systematic overview is presented for all included studies. A quantitative meta-analysis was conducted for hypertension and stroke.

RESULTS

Sixty-four papers were included in the review. The age range at cancer diagnosis was 0-24 years; age at the end of follow-up ranged from 7 to 71 years. Prevalence of cardiovascular late effects varied from 0% for stroke up to 70% for subclinical hypertension. Large heterogeneity was found regarding study size, study design, definition of endpoints, and investigation/examination method. The weighted average prevalence was 19.7% for hypertension and 2.3% for stroke. As no specific results for gender, cancer therapy, or age at cancer diagnosis were present in most papers, a detailed comparison and pooled analysis was difficult.

CONCLUSION

This review showed the vast range of cardiovascular late effects after childhood or adolescent cancer therapy. The differences between the papers prevented drawing a conclusive picture of the prevalence of cardiovascular late effects. Large cohort studies and better reporting are needed to improve the knowledge on this topic.

Review of phase I and II trials for Wilms' tumour - Can we optimise the search for novel agents?

Survival rates for patients with Wilms' tumour (WT) approximate 90% with refined use of currently available interventions. However, a subgroup of patients, with initial high-risk histopathology or relapsing disease, have a poor prognosis, and it is a challenge to identify and prioritise the development of new innovative approaches for these subgroups. We conducted a systematic literature search for published phase I and II clinical trials that registered patients with WTs and characterised the early phase trial activity, quantified response rates and highlighted avenues for further development. We identified 63 trials (48 phase I, three phase I/II, and 12 phase II trials) enrolling 214 patients with WTs, alongside other malignancies. The number of annually recruited WTs did not change significantly and was less than 20% of the potential candidates. The vast majority of the trials were conducted in North America, and 56 different interventions were investigated, including conventional chemotherapy and biologically targeted therapies. Overall, 33 WTs revealed some degree of tumour control. Of these, five patients demonstrated complete remission (2%), 15 patients partial response (7%) and 13 patients stable disease (6%). None of the included novel biologically targeted therapies emerged as promising interventions, and only conventional chemotherapy was able to induce a complete and partial response. We conclude that early phase trial recruitment of WTs is below expected levels, and the clinical outcome of the included patients is dismal. Improvement of the availability and recruitment to early phase trials for WTs, especially in Europe, is needed.

Outcome of patients with intracranial relapse enrolled on national Wilms Tumor Study Group clinical trials

BACKGROUND

The occurrence of brain metastases (at diagnosis or at relapse) in patients with Wilms tumor is very rare.

METHODS

We retrospectively reviewed the clinical characteristics of patients with Wilms tumor and relapse to the brain enrolled on the National Wilms Tumor Studies (NWTSs) 1-5.

RESULTS

Intracranial relapse was documented in 47 patients (0.5%). Of the 45 patients with adequate data, 26 (58%) patients were male. Thirty-eight (84%) patients had favorable histology Wilms tumor. In 30 patients (67%), the appearance of intracranial disease was preceded by relapse at another site. Ten patients did not have any disease-directed therapy. Surgical resection was attempted in 15 patients; gross total resection was achieved in 11 patients. Twenty-nine patients received brain irradiation; the median dose was 3,000 cGy (range 1,080-4,000 cGy). Twenty-seven patients received chemotherapy. The 5-year overall survival from the time of intracranial relapse was 28.7% (95% confidence interval: 14.4-43.1%). Nine patients (all favorable histology Wilms tumor) were alive with a median follow-up from brain relapse of 140 months (range 35-381 months). All nine survivors received radiation therapy, eight received chemotherapy, and four underwent surgery (two gross total resection, two partial resection). The overall survival after brain metastases of the NWTS-5 patients was significantly higher than the overall survival of the NWTS 1-4 patients (P value = 0.029, log-rank test).

CONCLUSIONS

Patients with Wilms tumor recurrence involving the brain may have durable survival, particularly those treated in recent years. Multimodality therapy including radiation and chemotherapy should be considered for these patients.

Clinical Outcome and Biological Predictors of Relapse After Nephrectomy Only for Very Low-risk Wilms Tumor: A Report From Children's Oncology Group AREN0532

OBJECTIVE

To determine if observation alone after nephrectomy in very low-risk Wilms tumor (defined as stage I favorable histology Wilms tumors with nephrectomy weight <550g and age at diagnosis <2 years) results in satisfactory event-free survival and overall survival, and to correlate relapse with biomarkers.

PATIENTS AND METHODS

The AREN0532 study enrolled patients with very low-risk Wilms tumor confirmed by central review of pathology, diagnostic imaging, and surgical reports. After nephrectomy, patients were followed without adjuvant chemotherapy. Evaluable tumors were analyzed for WT1mutation, 1p and 16q copy loss, 1q copy gain, and 11p15 imprinting. The study was powered to detect a reduction in 4-year EFS from 87% to 75% and overall survival from 95% to 88%.

RESULTS

A total of 116 eligible patients enrolled with a median follow up of 80 months (range: 5-97 months). Twelve patients relapsed. Estimated 4-year event-free survival was 89.7% (95% confidence interval 84.1-95.2%) and overall survival was 100%. First sites of relapse were lung (n = 5), tumor bed (n = 4), and abdomen (n = 2), with one metachronous tumor in the contralateral kidney (n = 1) at a median time of 4.3 months for those who relapsed (range 2.3-44 months). The presence of intralobar (P = 0.46) or perilobar rests (P = 1.0) were not associated with relapse (P = 0.16). 1q gain, 1p and 16q loss, and WT1 mutation status were not associated with relapse. 11p15 methylation status was associated relapse (20% relapse with loss of heterozygosity, 25% with loss of imprinting, and 3.3% relapse with retention of the normal imprinting (P = 0.011)).

CONCLUSIONS

Most patients meeting very low-risk criteria can be safely managed by nephrectomy alone with resultant reduced exposure to chemotherapy. Expansion of an observation alone strategy for low-risk Wilms tumor incorporating both clinical features and biomarkers should be considered.

Recent advances in the management of Wilms' tumor

The objective of this article is to present an overview of recent trends in the management of Wilms’ tumor. With improved survival rates in the past few decades, critical long-term adverse therapy effects (such as renal insufficiency, secondary malignancies, and heart failure) and prevention measures (i.e. nephron-sparing surgery and minimizing the use of radiotherapy) have gained worldwide attention. Specific disease biomarkers that could help stratify high-risk from low-risk patients, and therefore fine-tune management, are in great demand. Ultimately, we aim to enhance clinical outcomes and maintain or improve current survival rates while avoiding undesirable treatment side effects and minimizing the exposure and intensity of chemotherapy and radiotherapy.

Renal Tumors in Children Younger Than 12 Months of Age: A 65-Year Single Institution Review

Wilms tumor (WT) is the most prevalent pediatric renal tumor and most commonly occurs between ages 1 and 5 years. Data are lacking on children younger than 12 months with renal tumors. The cancer registry at the authors' institution was queried to identify patients 12 months and younger with renal masses. Demographics, clinical presentation, histopathology, stage, and survival outcomes were reviewed. The most common presenting symptoms included an asymptomatic abdominal mass (73%) and hematuria (9%). Histopathology revealed WT in 73% of patients, mesoblastic nephroma in 20%. Of those infants younger than 1 month of age, mesoblastic nephroma was the most common histopathology (68%). The 5-year overall survival (OS) was 93%, and 5-year event-free survival (EFS) was 93% for the entire group. For patients with WT, 5-year OS was 88% and 5-year EFS was 83%. Outcomes for congenital mesoblastic nephroma were excellent with 5-year OS and EFS of 100%. Reasons for good prognosis may be multifactorial and may include frequent well child checks in the first year of life and favorable histology. Patients in this age group are more likely to be classified as very low risk and may be treated with surgical resection alone.

Biology and treatment of renal tumours in childhood

In Europe, almost 1000 children are diagnosed with a malignant renal tumour each year. The vast majority of cases are nephroblastoma, also known as Wilms' tumour (WT). Most children are treated according to Société Internationale d'Oncologie Pédiatrique Renal Tumour Study Group (SIOP-RTSG) protocols with pre-operative chemotherapy, surgery, and post-operative treatment dependent on stage and histology. Overall survival approaches 90%, but a subgroup of WT, with high-risk histology and/or relapsed disease, still have a much poorer prognosis. Outcome is similarly poor for the rare non-WT, particularly for malignant rhabdoid tumour of the kidney, metastatic clear cell sarcoma of the kidney (CCSK), and metastatic renal cell carcinoma (RCC). Improving outcome and long-term quality of life requires more accurate risk stratification through biological insights. Biomarkers are also needed to signpost potential targeted therapies for high-risk subgroups. Our understanding of Wilms' tumourigenesis is evolving and several signalling pathways, microRNA processing and epigenetics are now known to play pivotal roles. Most rhabdoid tumours display somatic and/or germline mutations in the SMARCB1 gene, whereas CCSK and paediatric RCC reveal a more varied genetic basis, including characteristic translocations. Conducting early-phase trials of targeted therapies is challenging due to the scarcity of patients with refractory or relapsed disease, the rapid progression of relapse and the genetic heterogeneity of the tumours with a low prevalence of individual somatic mutations. A further consideration in improving population survival rates is the geographical variation in outcomes across Europe. This review provides a comprehensive overview of the current biological knowledge of childhood renal tumours alongside the progress achieved through international collaboration. Ongoing collaboration is needed to ensure consistency of outcomes through standardised diagnostics and treatment and incorporation of biomarker research. Together, these objectives constitute the rationale for the forthcoming SIOP-RTSG 'UMBRELLA' study.

"Zero-Ischemia" Laparoscopic-assisted Partial Nephrectomy for the Management of Selected Children With Wilms Tumor Following Neoadjuvant Chemotherapy

OBJECTIVE

To describe the experience and technique of zero-ischemia laparoscopic-assisted partial nephrectomy at The Hospital for Sick Children, as an alternative to the traditional open approach for nephron-sparing surgery (NSS) in selected children with Wilms tumor (WT).

MATERIALS AND METHODS

Patients with diagnosis of WT treated with neoadjuvant chemotherapy and who underwent laparoscopic-assisted NSS at the Hospital for Sick Children from 2012 to 2016 were identified and their charts were reviewed retrospectively. Patients underwent laparoscopic exploration, lymph node sampling, kidney mobilization, vascular control, and adrenal sparing. This was followed by open NSS through a small flank incision; no clamping of the hilum or major renal branches was performed.

RESULTS

Six patients were identified; all patients underwent successful resection. One patient required radical nephrectomy due to inability to safely define negative margins. Tumors ranged in size from 0.9 to 5.6 cm in diameter. Mean operating time was 293 ± 50.2 minutes, with an average duration of pneumoperitoneum of 216 ± 27 minutes. Intraoperative blood loss was negligible. No tumor spillages occurred. Postoperative pathology revealed negative margins in all resected specimens. One case of urine leak occurred postoperatively, which resolved spontaneously. Renal function was preserved in all children. At a mean follow up of 11.5 months, all patients have been recurrence free.

CONCLUSION

The herein presented strategy allows for safe nephron-sparing resection of selected WT with acceptable morbidity, good short-term disease-free survival, and potentially better cosmesis and recovery than traditional open surgery. This preliminary experience suggests that minimally invasive options for NSS in children merit further evaluation.

Association of Chromosome 1q Gain With Inferior Survival in Favorable-Histology Wilms Tumor: A Report From the Children's Oncology Group

PURPOSE

The goal of this study was to analyze the association of copy number gain of 1q in favorable-histology Wilms tumors (FHWTs) with event-free survival (EFS) and overall survival (OS) within each tumor stage and with 1p and 16q copy number loss and/or loss of heterozygosity.

METHODS

Unilateral FHWTs from 1,114 patients enrolled in National Wilms Tumor Study-5 that were informative for 1p and 16q microsatellite markers (previously determined) and informative for 1q gain, 1p loss, and 16q loss using multiplex ligation-dependent probe amplification were analyzed.

RESULTS

Eight-year EFS was 86% (95% CI, 84% to 88%) for the entire cohort. Of 1,114 patients, 317 tumors (28%) displayed 1q gain. Eight-year EFS was 77% for those with 1q gain and 90% for those lacking 1q gain (P < .001). Eight-year OS was 88% for those with 1q gain and 96% for those lacking 1q gain (P < .001). Within each disease stage, 1q gain was associated with inferior EFS (stage I, 85% v 95%; P = .0052; stage II, 81% v 87%; P = .0775; stage III, 79% v 89%; P = .01; stage IV, 64% v 91%; P = .001). OS was significantly inferior in patients with stage I (P < .0015) and stage IV disease (P = .011). With multivariable analysis, 1q gain was associated with an increased relative risk of relapse of 2.4 (P < .001), whereas 1p loss was not, despite significance on univariable analysis.

CONCLUSION

Gain of 1q is associated with inferior survival in unilateral FHWTs and may be used to guide risk stratification in future studies.