A Comparison of Renal Function Outcomes After Nephron-sparing Surgery and Radical Nephrectomy for Nonsyndromic Unilateral Wilms Tumor

Efficacy and late kidney effects of nephron-sparing surgery in the management of unilateral Wilms tumor: a systematic review and meta-analysis

To evaluate the efficiency and long-term renal function of nephron sparing surgery (NSS) in unilateral WT patients compared with radical nephrectomy (RN). The review was performed following Cochrane Handbook guidelines and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We searched five databases (Pubmed, Embase, Scopus, Web of Science and Cochrane) for studies reporting the efficiency and late renal function of NSS and/or RN on February 10, 2023. Comparative studies were evaluated by Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) and RoB 2.0. Assessed outcomes included survival rate, relapse rate, eGFR, renal dysfunction and hypertension. 26 studies involving 10322 unilateral WT cases underwent RN and 657 unilateral WT cases underwent NSS were enrolled. Overall effect estimates demonstrated that NSS significantly increased eGFR at follow-up (SMD, 0.38; 95% CI 0.05-0.72; p = 0.025) compared to that at diagnosis, and RN did not significantly decrease eGFR at follow-up (SMD, - 0.33; 95% CI - 0.77-0.11; p = 0.142) compared to that at diagnosis. Moreover, no significant difference was found in outcomes of survivability (OR, 1.38; 95% CI 0.82-2.32; p = 0.226), recurrence (OR, 0.62; 95% CI 0.34-1.12; p = 0.114), eGFR at follow-up (SMD, 0.16; 95% CI - 0.36-0.69; p = 0.538), renal dysfunction (OR, 0.36; 95% CI 0.07-1.73; p = 0.200) and hypertension (OR, 0.17; 95% CI 0.03-1.10; p = 0.063). Current evidence suggests that NSS is safe and effective for unilateral WT patients, because it causes better renal function and similar oncological outcomes compared with RN. Future efforts to conduct more high-quality studies and explore sources of heterogeneity is recommended.

Surgery in Bilateral Wilms Tumor-A Single-Center Experience

The treatment of bilateral Wilms tumors (BWT) involves curing the cancer, preserving long-term renal function, and maintaining a good quality of life. Established methods for achieving these goals include preoperative chemotherapy and nephron-sparing surgery (NSS). This study aimed to evaluate the experience of a single institution in treating patients with BWT. We analyzed cases of BWT treated at the Pediatric Oncology Institute-GRAACC-Federal University of São Paulo over a period of 35 years. Bleeding control was performed with manual compression of the renal parenchyma. Thirty-three patients were included in the study. Thirty cases were synchronous tumors. The mean age at diagnosis was 30.4 months (±22 m) and 66.7% were girls. The median follow-up period was 83 months. Neoadjuvant chemotherapy was the primary approach in most patients (87.9%), with a simultaneous upfront surgical approach performed in 84.8%. Most patients underwent bilateral NSS (70.4%). There were no early complications in this series, but 39.4% had clinical complications. The five-year survival rate was 76%. Therefore, it is clear that the surgical approach to BWT plays a crucial role in achieving good outcomes. However, it is difficult to standardize surgical techniques and technology may have the potential to enhance safety.

RENAL nephrometry scoring system in bilateral Wilms tumor: predictive application

AIM

This study aims to explore the application of RENAL nephrometry scoring system in bilateral Wilms tumor (BWT).

METHODS

A retrospective review of patients with BWT from January 2010 to June 2022 was performed. Each kidney unit of the BWT was evaluated independently and scored according to RENAL nephrometry scoring system by 2 blinded reviewers, and reviewers were blinded to what surgery the patients ultimately had. Discrepancies were evaluated by a third reviewer to reach a consensus. Tumor anatomical characteristics were summarized and compared.

RESULTS

29 patients with 53 kidney units were included in the study. 53 kidney units included 12 (22.6%) low-complexity, 9 (17.0%) intermediate-complexity, and 32 (60.4%) high-complexity. 2 kidney units (3.8%) had tumor thrombus, and 14 (26.4%) had multiple lesions. A total of 42 kidney units (79.2%) underwent initial nephron-sparing surgery (NSS) and 11 (20.8%) underwent radical nephrectomy. Less complexity tumors were observed in the NSS group. Of the 42 kidney units undergoing initial NSS, 26 were performed in vivo and 16 ex vivo via autotransplantation. The latter group featured a higher complexity. During follow-up, 22 patients survived and 7 died, no statistically significant tumor complexity was observed between the two groups.

CONCLUSIONS

The anatomical characteristics of BWT are complex. Despite this study did not indicate that the complexity correlates with prognosis, low-complexity tumors were candidates for NSS, and kidney autotransplantation provided a feasible procedure for high-complexity tumors. A refined system is required due to multiple lesions and tumor thrombus.

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

Background

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

Materials and methods

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

Results

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

Conclusion

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

Evidence-based surgical guidelines for treating children with Wilms tumor in low-resource settings

BACKGROUND

Survival of Wilms tumor (WT) is > 90% in high-resource settings but < 30% in low-resource settings. Adapting a standardized surgical approach to WT is challenging in low-resource settings, but a local control strategy is crucial to improving outcomes.

OBJECTIVE

Provide resource-sensitive recommendations for the surgical management of WT.

METHODS

We performed a systematic review of PubMed and EMBASE through July 7, 2020, and used the GRADE approach to assess evidence and recommendations.

RECOMMENDATIONS

Initiation of treatment should be expedited, and surgery should be done in a high-volume setting. Cross-sectional imaging should be done to optimize preoperative planning. For patients with typical clinical features of WT, biopsy should not be done before chemotherapy, and neoadjuvant chemotherapy should precede surgical resection. Also, resection should include a large transperitoneal laparotomy, adequate lymph node sampling, and documentation of staging findings. For WT with tumor thrombus in the inferior vena cava, neoadjuvant chemotherapy should be given before en bloc resection of the tumor and thrombus and evaluation for viable tumor thrombus. For those with bilateral WT, neoadjuvant chemotherapy should be given for 6-12 weeks. Neither routine use of complex hilar control techniques during nephron-sparing surgery nor nephron-sparing resection for unilateral WT with a normal contralateral kidney is recommended. When indicated, postoperative radiotherapy should be administered within 14 days of surgery. Post-chemotherapy pulmonary oligometastasis should be resected when feasible, if local protocols allow omission of whole-lung irradiation in patients with nonanaplastic histology stage IV WT with pulmonary metastasis without evidence of extrapulmonary metastasis.

CONCLUSION

We provide evidence-based recommendations for the surgical management of WT, considering the benefits/risks associated with limited-resource settings.

Nephron sparing surgery outcomes in Wilms' tumor: is it ready for primetime?

PURPOSE

Radical nephrectomy is the gold standard in Wilms tumor (WT) treatment and is combined with adjuvant treatment in early stage disease or performed after neo adjuvant therapy in advanced disease. With the development of novel adjuvant and neoadjuvant therapeutic strategies, there is increasing interest in organ preserving procedures in several adult malignancies. Potential long-term complications of living with a single kidney include hyperfiltration syndrome, hypertension, and fluid retention. If NSS (Nephron Sparing Surgery) were to be adopted for the treatment of WT it would be necessary to preserve the gains in Overall Survival (OS) seen with current treatment protocols. With this in mind we undertook a study of outcomes of NSS performed in the USA using a large population-based registry.

METHODS

We retrospectively queried the SEER Research Plus 18-registries Database 2010-2018 for patients 18 years old or younger with Wilms tumor as determined by ICD-O-3 code 8960. Clinical and demographic data was extracted, and statistical analysis was performed in GraphPad PRISM 9 with bivariate analysis and log-rank analysis to determine survival.

RESULTS

1087 patients with Wilms tumor were identified. 73 (6.72%) underwent nephron-sparing surgery. The final cohort consisted of 45 patients (64%) who underwent unilateral NSS and 25 patients (36%) who underwent bilateral NSS. Three were excluded from analysis due to non-renal origin of tumor. Mean age was 3.214 years (std dev 3.807). Demographics were similar between the groups, apart from younger age associated with bilateral tumor (p = 0.0441). No differences were found between radiation use (p = 0.4280), chemotherapy use (p = 0.5479), tumor size (p = 0.2186), positive regional lymph nodes (p = 0.707). Log-rank analysis demonstrated that cancer-specific survival was not significantly different between unilateral and bilateral NSS or radical nephrectomy (p = 0.4539).

CONCLUSION

NSS may preserve renal function long-term, an important consideration in the pediatric population. Prospective study is necessary to select the appropriate patient subsets who may benefit from NSS in WT.

Multidisciplinary Treatment Strategies for Wilms Tumor: Recent Advances, Technical Innovations and Future Directions

Significant progress has been made in the management of Wilms tumor (WT) in recent years, mostly as a result of collaborative efforts and the implementation of protocol-driven, multimodal therapy. This article offers a comprehensive overview of current multidisciplinary treatment strategies for WT, whilst also addressing recent technical innovations including nephron-sparing surgery (NSS) and minimally invasive approaches. In addition, surgical concepts for the treatment of metastatic disease, advances in tumor imaging technology and potentially prognostic biomarkers will be discussed. Current evidence suggests that, in experienced hands and selected cases, laparoscopic radical nephrectomy and laparoscopic-assisted partial nephrectomy for WT may offer the same outcome as the traditional open approach. While NSS is the standard procedure for bilateral WT, NSS has evolved as an alternative technique in patients with smaller unilateral WT and in cases with imminent renal failure. Metastatic disease of the lung or liver that is associated with WT is preferably treated with a three-drug chemotherapy and local radiation therapy. However, surgical sampling of lung nodules may be advisable in persistent nodules before whole lung irradiation is commenced. Several tumor markers such as loss of heterozygosity of chromosomes 1p/16q, 11p15 and gain of function at 1q are associated with an increased risk of recurrence or a decreased risk of overall survival in patients with WT. In summary, complete resection with tumor-free margins remains the primary surgical aim in WT, while NSS and minimally invasive approaches are only suitable in a subset of patients with smaller WT and low-risk disease. In the future, advances in tumor imaging technology may assist the surgeon in defining surgical resection margins and additional biomarkers may emerge as targets for development of new diagnostic tests and potential therapies.

Long-term kidney function in children with Wilms tumour and constitutional WT1 pathogenic variant

BACKGROUND

Wilms tumour (WT) survivors, especially patients with associated syndromes or genitourinary anomalies due to constitutional WT1 pathogenic variant, have increased risk of kidney failure. We describe the long-term kidney function in children with WT and WT1 pathogenic variant to inform the surgical strategy and oncological management of such complex children.

METHODS

Retrospective analysis of patients with WT and constitutional WT1 pathogenic variant treated at a single centre between 1993 and 2016, reviewing genotype, phenotype, tumour histology, laterality, treatment, patient survival, and kidney outcome.

RESULTS

We identified 25 patients (60% male, median age at diagnosis 14 months, range 4-74 months) with WT1 deletion (4), missense (2), nonsense (8), frameshift (7), or splice site (4) pathogenic variant. Thirteen (52%) had bilateral disease, 3 (12%) had WT-aniridia, 1 had incomplete Denys-Drash syndrome, 11 (44%) had genitourinary malformation, and 10 (40%) had no phenotypic anomalies. Patient survival was 100% and 3 patients were in remission after relapse at median follow-up of 9 years. Seven patients (28%) commenced chronic dialysis of which 3 were after bilateral nephrectomies. The overall kidney survival for this cohort as mean time to start of dialysis was 13.38 years (95% CI: 10.3-16.4), where 7 patients experienced kidney failure at a median of 5.6 years. All of these 7 patients were subsequently transplanted. In addition, 2 patients have stage III and stage IV chronic kidney disease and 12 patients have albuminuria and/or treatment with ACE inhibitors. Four patients (3 frameshift; 1 WT1 deletion) had normal blood pressure and kidney function without proteinuria at follow-up from 1.5 to 12 years.

CONCLUSIONS

Despite the known high risk of kidney disease in patients with WT and constitutional WT1 pathogenic variant, nearly two-thirds of patients had sustained native kidney function, suggesting that nephron-sparing surgery (NSS) should be attempted when possible without compromising oncological risk. Larger international studies are needed for accurate assessment of WT1genotype-kidney function phenotype correlation.

Expanding the Use of Nephron-Sparing Surgery for Wilms Tumor

Radical nephrectomy combined with contemporary chemotherapeutic and radiation therapy protocols has drastically improved outcomes for children with Wilms tumor. Patients with bilateral disease and a syndrome predisposing to tumor development have necessitated the use of nephron-sparing surgery in select cases. Success in managing these patients has increased the indication for partial nephrectomy, although current guidelines for unilateral Wilms tumor are limited. Given that children are being cured with increasing success, recent focus has shifted to long-term health outcomes in addition to tumor treatment. Specifically, renal function has an impact on long-term cardiovascular health and events. Adult outcomes with partial nephrectomy provide a guideline for a paradigm shift in the management of children with Wilms tumor, particularly with advances in imaging and adjuvant therapy. The data are limited for children undergoing partial nephrectomy for unilateral Wilms tumor and outcomes for larger tumors will need to be studied closely in future trials. Increased utilization of neoadjuvant chemotherapy could further expand the number of patients eligible for partial nephrectomy.

Kidney injury rates after unilateral nephrectomy in childhood-a systematic review and meta-analysis

BACKGROUND

Unilateral nephrectomy is a relatively common procedure in children which results in a solitary functioning kidney (SFK). Living with an SFK predisposes to kidney injury, but it remains unknown which children are most at risk. We aimed to investigate kidney injury rates in patients who underwent unilateral nephrectomy in childhood and to investigate differences among nephrectomies performed for a congenital anomaly, malignancy or other condition.

METHODS

MEDLINE and EMBASE were searched for studies reporting kidney injury rates [i.e. proteinuria, hypertension and/or a decreased glomerular filtration rate (GFR)] of patients who underwent unilateral nephrectomy during childhood. Studies including five or more patients with at least 12 months of follow-up were eligible. Analyses were performed using random effects models and stratified by indication for nephrectomy. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines were used for reporting.

RESULTS

Over 5000 unique articles were screened, of which 53 studies reporting on >4000 patients were included in the analyses. Proteinuria, hypertension and a decreased GFR were present in 15.3, 14.5 and 11.9% of patients, respectively. Heterogeneity among the studies was large in several subgroups, impairing quantitative meta-analyses. However, none of our analyses indicated differences in injury rates between a congenital anomaly or malignancy as an indication for nephrectomy.

CONCLUSIONS

Unilateral nephrectomy during childhood results in signs of kidney injury in >10% of patients, with no clear difference between the indications for nephrectomy. Therefore, structured follow-up is necessary in all children who underwent nephrectomy, regardless of the indication.

Nephron-Sparing Surgery in Nonsyndromic Unilateral Wilms' tumor: An Insight into the Ongoing Surgical Controversy

BACKGROUND

Unilateral Wilms' tumor (uWT) is the most common renal malignancy in the pediatric population. Although the onset of surgical intervention like radical nephrectomy (RN) has substantially reduced the mortality rate, recent evidence has raised concerns regarding several postoperative complications associated with this procedure. Nephron-sparing surgery (NSS) has been reported to avoid such postoperative complications and have high technical success rate. However, not much literature is available comparing the efficacy of RN and NSS for managing nonsyndromic uWT, which makes it less acceptable globally.

MATERIALS AND METHODS AND RESULTS

A systematic identification of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines on four academic databases: MEDLINE, Scopus, EMBASE, and CENTRAL. Out of 1017 records, 20 manuscripts including 312 patients were included in the review; 4 patients treated by the author (unpublished data) have also been included. The studies included 7 retrospective case series with no comparison group, 4 retrospective case series with comparison group, 4 retrospective series with a cursory mention of NSS in uWT, 2 case reports, 1 protocolized prospective trial with comparison group, 1 administrative database analysis with comparison group, and 1 randomized controlled study. In all, 316 patients with nonsyndromic uWT were studied. The pretherapy volumes of the WT ranged from 2.4 to 640 ml. Majority of them were administered preoperative chemotherapy. About half of the patients (n = 159) (50.3%) were Stage I tumors. Stage II, III, and IV tumors were seen in 23 (7.3%), 20 (6.3%), and 3 (1%) patients. Stage was not specified in 111 (35.1%) patients. Majority of them were "intermediate risk" WT. All these tumors were nonanaplastic. Surgical margins were reported positive in 13 (4%) patients. Overall and event-free survivals were 100% in most of the studies; only handful of relapses were noted in this systematic review.

CONCLUSIONS

This qualitative systematic review recommends the use of NSS for nonsyndromic uWT. The procedure accounts for higher postoperative renal function and lesser incidence of hypertension as compared to the radical nephrectomy. Overall and event-free survivals are comparable or even better with NSS.

Wilms tumor

The objectives for the treatment of Wilms tumor in both the Children's Oncology Group (COG) and the International Society of Paediatric Oncology (SIOP) have focused on improving cure rates and minimizing toxicity by limiting the use of radiation and doxorubicin. Although the timing of surgery is different in COG (upfront surgery) and SIOP (upfront chemotherapy with delayed surgery), both are effective strategies and have the same survival. Fewer patients are treated with radiotherapy in the SIOP trials but with higher doses. The prognostic significance of biological markers such as 1q gain and clinical outcomes with novel radiation techniques such as intensity modulated radiation therapy will be determined in upcoming clinical trials. A closer collaboration between COG and SIOP could help promote research and improve the clinical outcomes of children with Wilms tumor.

Renal and Hepatic Health After Childhood Cancer

Childhood cancer survivors (CCSs) are at risk for renal and hepatic complications related to curative cancer treatments. Although acute renal and hepatic toxicities of cancer treatments are well described, data regarding long-term and late-occurring sequelae or their associations with acute sequelae are less robust. This article highlights the literature on the prevalence of and risk factors for late renal and hepatic toxicity in CCSs. Studies investigating these outcomes are needed to inform surveillance practices and the development of future frontline cancer treatment protocols.

Effectiveness of Nephron Sparing Surgery and Radical Nephrectomy in the Management of Unilateral Wilms Tumor: A Meta-Analysis

Background: Unilateral Wilms tumor is the most common renal malignancy in the pediatric population. Although the onset of surgical intervention like radical nephrectomy has substantially reduced the mortality rate, recent evidence has raised concerns regarding several postoperative complications associated with this procedure. Nephron sparing surgery has been reported to avoid such postoperative complications and have high technical success rate. However, no attempt to date has been made to synthesize the evidence comparing the efficacy of radical nephrectomy and nephron sparing surgery for managing unilateral Wilms tumor. Methods and Results: To metastatistically compare the efficiency of radical nephrectomy with nephron sparing surgery for managing unilateral Wilms tumor, a systematic identification of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines on four academic databases: MEDLINE, Scopus, EMBASE, and CENTRAL. A meta-analysis comparing renal function (estimated glomerular filtration rate), survival rate, and rate of relapse was performed to compare the efficacy of radical nephrectomy and nephron sparing surgery. Out of 1,283 records, 20 articles including 5,246 children (mean age, 4.3 ± 3.0 years) were included in this review. Radical nephrectomy was performed on 11 of the included studies, whereas nephron sparing surgery was performed on five studies. Two studies compared the efficacy of both interventions. The meta-analysis reveals the beneficial effects of nephron sparing surgery (Hedge's g, 0.76) as compared to radical nephrectomy (-0.16) for the estimated glomerular filtration rate for children with unilateral Wilms tumor. Moreover, higher survivability (0.59) and lesser occurrence of relapse were (-1.0) also reported for cases operated with nephron sparing surgery. Conclusion: The current meta-analysis recommends the use of nephron sparing surgery for unilateral Wilms tumor. The procedure accounts for higher survivability and postoperative renal function and lesser incidence of relapse as compared to radical nephrectomy.

International Publication Patterns on Operative Management of Wilms Tumor: A Review by Surgeon Specialty and Surgical Modality

OBJECTIVE

To review the temporal trends in the published literature of the surgical management of Wilms tumor (WT) relative to surgical modality and authorship by surgeon specialty (pediatric urology [PU] vs pediatric surgery [PS]).

METHODS

The MEDLINE/PubMed database was queried for manuscripts published by PU or PS including operative management of WT from 1993-2017. After manuscript review, 187 of 2420 studies were included. Studies were compared by author specialty, country of origin, and represented patients.

RESULTS

PU published 32% of included publications. The proportion of first author publications by PU increased over time (25% from 1993-2005 to 39% from 2006-2017, P = .029). While PU were first author on 44% of studies in North America, they were relatively underrepresented internationally. PU and PS were equally likely to be first author on cooperative group studies, which accounted for 19% of the overall publications. 14,958 patients underwent extirpative surgery for WT. There was a small increase in publications reporting the use of minimally-invasive surgery (MIS) and nephron-sparing surgery (NSS) over time (<1% and 4% from 1993-2005 to 2% and 7% from 2006-2017, respectively, P <.001). Compared to PS, PU were significantly more likely to publish on patients managed with MIS and NSS (P = .006 and P < 0.001 respectively).

CONCLUSION

Publications by PU on the surgical management of WT are increasing over time, but are still fewer than PS. PU appeared to be the drivers of the temporal trend towards the increasing use of MIS and NSS in the published literature.

Evaluation of Nephron-Sparing Surgery as Potential Risk Factor for Relapse in Unilateral Wilms Tumor

BACKGROUND

The aim of the study was to assess the prognostic significance of nephron-sparing surgery (NSS) without tumor size limits as a risk factor for relapse in children with unilateral Wilms Tumor (WT).

METHODS

A 28-y retrospective single-center review was performed. Prognostic relevance of age, gender, stage, histology, nephrectomy (N), and NSS was analyzed.

RESULTS

Sixty-nine cases (42 females and 27 males) with WT, off-therapy from 21 to 325 mo after chemotherapy mainly based on the International Society of Pediatric Oncology trials, were treated at our institution. Five cases were excluded (three children with synchronous bilateral WT and two adults with unilateral WT). Of 64 children with unilateral WT, 51 underwent N and 13 NSS without tumor size limits. Indeed, two-thirds of children who underwent NSS presented with a tumor diameter >4 cm. Overall, nine patients (14%) had a relapse (male-to-female ratio = 1:8). Initial surgery was N in eight cases and NSS in another one. Relapse rates in N and NSS groups were 15.7% and 7.7% (P = nonsignificant), respectively; the relapse rates in N and NSS groups were 8.6% and 7.7% (P = nonsignificant) for stages I-II unilateral WT cohort, respectively. On univariate analysis, factors correlated with probability of relapse were unfavorable histology (P < 0.002) and stage III disease (P < 0.01).

CONCLUSIONS

In unilateral WT, NSS, whenever feasible, does not seem to increase the risk of recurrence. A multicenter prospective trial is required to carefully evaluate this risk.

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.

Organ-sparing procedures in GU cancer: part 1-organ-sparing procedures in renal and adrenal tumors: a systematic review

PURPOSE

Organ-sparing surgery (OSS) for the kidney and adrenals has emerged as the need for preservation of function is paramount in patients with poor functional reserve. As reports increasingly showed that oncological outcomes were equivalent to radical excision, elective OSS became a viable alternative in patients with otherwise normal reserve. In this review, we summarize the current knowledge of OSS for adrenal and renal tumors.

MATERIALS AND METHODS

PubMed, Web of Science and Cochrane Library Central Search were searched for recently published articles up to December 2017. The following keywords were used; "partial adrenalectomy", "adrenal sparing", "partial nephrectomy", "nephron sparing", "kidney/renal cancer".

RESULTS

Partial adrenalectomy became an attractive alternative to total adrenalectomy avoiding adrenal insufficiency. Both minimally invasive surgery and ablative techniques were increasingly reported for adrenal OSS with adequate residual adrenal function and excellent oncological outcome. Radical nephrectomy remained for many years as the gold standard of treatment for organ-confined renal cell carcinoma. As the need to reduce the impact on renal function, more conservative approaches were utilized. Soon, the non-inferiority of nephron-sparing surgery to that of radical excision became evident and elective partial nephrectomy was gaining ground as the standard of care for small renal masses in patients with normal contralateral kidneys.

CONCLUSIONS

Herein, we present a comprehensive review of the current status of OSS in renal and adrenal tumors.

Estimated glomerular filtration rate after nephrectomy for Wilms tumor

BACKGROUND

The aim of this study was to assess long-term residual kidney function after unilateral nephrectomy for non-syndromic Wilms tumor (NSWT).

METHODS

Of the patients who underwent one-sided NSWT at Tohoku University Hospital between 1977 and 2003, nine were followed up until age ≥18 years. For these nine patients, we retrospectively evaluated estimated glomerular filtration rate (eGFR) in childhood (3-10 years old), adolescence (11-17 years old) and adulthood (≥18 years).

RESULTS

Mean age at the last follow up was 23.0 years. Tumor classification was as follows: stage I tumor, n = 6; stage II tumor, n = 3; mixed-type nephroblastoma, n = 8; and congenital mesoblastic nephroma, n = 1. Mean eGFR was 101.3 ± 21.2 mL/min/1.73 m² in childhood, 106.0 ± 32.1 mL/min/1.73 m² in adolescence and 100.5 ± 20.7 mL/min/1.73 m² in adulthood. Therefore, no significant change in eGFR was observed over the three life stages evaluated. Further, none of the patients met the diagnostic criteria for chronic kidney disease by early adulthood.

CONCLUSIONS

eGFR after unilateral nephrectomy in patients with NSWT remained ≥60 mL/min/1.73 m² during the transition from childhood to early adulthood, with no development of chronic kidney disease or end-stage kidney failure.

Evaluation of renal tumors in children

OBJECTIVE

Renal tumors are not uncommon in children. In this study, we aimed to evaluate the clinical and pathological features of renal tumors in children.

MATERIAL AND METHODS

Between January 2008 and December 2017, the records of children with renal tumors in our institution were retrospectively analyzed. Data collected were composed of demographic and clinical characteristics including gender, age at time of diagnosis, symptoms, laterality of the tumor and pathological evaluation.

RESULTS

A total of 48 children with renal tumor (28 males and 20 females) were included in the study. They were diagnosed at mean age of 53.26±46.64 months (range: 1-192) and the mean follow-up period was 73.45±48.92 months (range: 6-120). The most common symptom was a lump or mass in the area of the kidneys (45.8%), abdominal pain and hematuria (14.6%). Four patients (8.3%) were diagnosed at antenatal period. 68.8% of the children had Wilms tumor and the major histological groups of non-Wilms renal tumors were renal cell carcinoma (12.5%), congenital mesoblastic nephroma (10.4%) and angiomyolipoma (4.2%). 10.4% of the children had bilateral tumors and one patients had Wilms tumor with horseshoe kidney. 87.5% of the children were treated with surgery and of those 7 (14.5%) underwent nephron-sparing surgery. The patients had chemotherapy and radiotherapy (83.3% and 41.7%, respectively). Seven patients (14.6%) died during follow-up.

CONCLUSION

Wilms tumor is the most common pediatric renal neoplasm. On the other hand, we showed that considerable number of children with renal tumors had non-Wilms tumors including renal cell carcinoma, congenital mesoblastic nephroma and angiomyolipoma.

Case Report: Nephron-sparing Surgery in a Patient With Bilateral Multifocal Wilms Tumor

We present a case of bilateral multifocal Wilms tumor in a nonsyndromic 12-month-old male. Our management approach included 12 weeks of preoperative chemotherapy for maximal tumor shrinkage and, despite the central location of the tumors, successful staged bilateral nephron-sparing surgery. We advocate for a broader application of nephron-sparing surgery in Wilms tumor cases with the goal of preserving renal function without compromising oncologic outcomes.

Collaborating with our adult colleagues: A case series of robotic surgery for suspicious and cancerous lesions in children and young adults performed in a free-standing children's hospital

BACKGROUND

In adult urologic oncology the use of robotics has become commonplace; in pediatric urology it is rare. Herein, we describe a collaboration between an adult and a pediatric urologist performing robotic surgery for children and young adults with suspicious or cancerous genitourinary (GU) lesions.

OBJECTIVES

To evaluate clinical and oncologic outcomes in children and young adults undergoing robotic surgery for suspicious or cancerous lesions of the GU tract; to describe our collaborative model between an adult and pediatric surgeon at a free-standing children's hospital.

DESIGN

We retrospectively reviewed all robotic cases performed at our institution from 2014 to 2016 for patients with a GU malignancy or a suspicious mass. The surgeries were performed by a pediatric urologist with robotic experience and a fellowship-trained MIS adult urologist specializing in oncology. Perioperative and oncologic outcomes were recorded.

RESULTS

A total of eight robotic cases were performed: four partial nephrectomies (PN) with retroperitoneal lymph node dissection (LND) (OT 269-338 min, EBL 5-300 mL, LOS 3-6 days), one adrenalectomy with LND (6.4 cm mass; OT 172 min, EBL 5 mL, LOS 3 days), one nephrectomy with pericaval LND (9.8 cm mass; 234 min, EBL 25 mL, LOS 3 days), and two retroperitoneal LNDs (OT 572 and 508 min, EBL 250 and 100, LOS 3 and 4 days). Patient weights ranged from 14 to 79 kg (mean 53.4 kg). There were no major complications (Clavien 3-5). Pathology results for PN included papillary RCC (AJCC pT1aNx) and two cases of segmental cystic renal dysplasia with nephrogenic rests. Bilateral template RPLNDs yielded paratesticular rhabdomyosarcoma (43 nodes; COG low risk group II stage I) and mixed non-seminomatous germ cell tumor (74 nodes; COG stage III). The nephrectomy yielded an undifferentiated sarcoma, low grade; the adrenalectomy favorable-type ganglioneuroma.

DISCUSSION

In pediatrics, urologic oncology cases are often managed with open surgery. Our series demonstrates the feasibility of using the robotic approach in carefully selected cases. In doing so, the patient benefits from a minimally invasive surgery, while the surgeon benefits from robotic surgical dexterity. We seamlessly advanced these new techniques through a step-wise collaboration between an adult urologist who routinely performs robotic oncology procedures and a pediatric urologist experienced in robotics for benign conditions.

CONCLUSION

In this small series, we safely and effectively adapted adult robotic techniques for genitourinary oncology cases in children and young adults.

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.

Nephron-sparing surgery in the treatment of pediatric renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusions

PURPOSE

To investigate the safety and efficacy of nephron-sparing surgery (NSS) in the treatment of pediatric Xp11.2 translocation renal cell carcinoma (RCC).

METHODS

Clinical characteristics of 9 RCC children (7 males and 2 females) with Xp11.2 translocation who received NSS between January 1973 and December 2015 were retrospectively analyzed. The mean age was 7.8years (range: 4.5-13.5years). Xp11.2 translocation RCC was found in the left side in 4 patients and right in 5. 3 tumors were located in the upper pole of the kidney, 1 in the middle dorsal, 1 in the middle ventral and 4 in the lower pole. RCC presented with painless gross hematuria in 4 patients, abdominal mass in 1, and as an incidental finding by ultrasound examination in 4 patients. The mean course of hematuria was 3months (range: 1-7months). The mean tumor diameters were 3.7cm (range: 2.2-6.9cm).

RESULTS

All the patients received NSS with open transperitoneal approach. The mean operative time and estimated blood loss were 115min and 40ml, respectively. The time of renal pedicle clamping was 19-25min (mean: 21.5min). No complications (such as leakage of urine, prolonged drainage or secondary bleeding) were noted. No patients experienced local recurrence during the mean of 50.1-month follow-up (range: 13-117months). Intravenous urography (IVU) or contrast-enhanced CT was conducted at 6months after surgery which showed favorable kidney function in all patients.

CONCLUSION

Xp11.2 translocation RCC is a predominant pathological but biologically inert type of pediatric RCC. For Xp11.2 translocation RCC sized <4-7cm in diameter and located in one pole, NSS is safe and feasible.

TYPE OF STUDY

Treatment Studies, LEVEL IV.

[Is nephron-sparing surgery relevant for unilateral Wilms tumors?]

BACKGROUND

Wilms tumors (WTs) are the most frequent renal tumors in children. Radical nephrectomy (RN) remains the gold-standard surgical treatment for this type of cancer. Excellent results in overall survival (>90%) make it possible to consider nephronic preservation. The objective of this systematic review is to evaluate the relevance of nephron-sparing surgery (NSS) for the treatment of nonsyndromic unilateral Wilms tumor (UWT) in children.

METHODS

Articles in English related to "unilateral Wilms tumor, unilateral nephroblastoma, partial nephrectomy, nephron-sparing surgery, renal function" identified in the Medline library were screened and data were extracted to perform a qualitative systematic review.

RESULTS

We identified 377 articles, 14 of which were integrated into the analysis. Data on 4288 children were included, 3994 (93.1%) underwent RN, whereas 294 (6.8%) underwent NSS. Stage I anatomopathology resulted in 55.1% RN and 79% NSS. Overall survival and event-free survival were similar: respectively 95.7% and 92.8% after RN and 96 and 90.5% after NSS. Positive margin status was higher after NSS (8.5% vs 0.5%), but tumor rupture and local tumor recurrences were similar. The rate of mild to moderate renal function was higher after RN (42% vs 10% after NSS).

DISCUSSION

NSS is regularly performed for WT in case of bilateral or syndromic tumors, but the literature considering UWT does not show consensus. The superiority of NSS for renal outcomes has now been fully evaluated, but the main problem of this surgery in case of UWT is to ensure oncologic outcomes as good as outcomes after RN. WTs are usually massive tumors for which partial nephrectomy is contraindicated, but studies showed that chemotherapy before surgery could reduce tumor volume and make NSS possible. This review shows that NSS results seem to be as good as RN results and that preoperative chemotherapy should be highlighted for its participation in the reduction of the positive margin status. Although radiotherapy is used with caution because of its side effects, some studies showed that it gave excellent results for oncologic salvage after local recurrence. Constant progress in medical imaging and detection systems has led to the emergence of a new type of assistance for surgeons such as image reconstruction and vessel or urinary tract system segmentation. Virtual simulation of the operation based on a real case should help evaluate the feasibility of complex procedures in the near future.

CONCLUSION

NSS for UWT seems to be a credible therapeutic alternative. New technologies such as 3D reconstruction should help surgeons define the best parameters to select ideal tumors for this surgery in the near future. For the moment, small tumors (<4cm), distant from the renal hilum (ideally on the upper pole) that respect at least 50% of the renal parenchyma (ideally superficial with exophytic development) seem to be the perfect indication for NSS.

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.

The Evolving Role of Minimally Invasive Surgery in Pediatric and Adolescent Urologic Oncology

OBJECTIVE

This review aims at evaluating the current status of minimally invasive surgery at the difficult crossroad between the attractiveness of innovation faced against the solid outcomes offered by the current gold standard, specifically concerning pediatric and adolescent urologic oncology conditions.

METHODS

This is a critical review of the literature and current paradigms on the use of minimally invasive surgery for pediatric and adolescent urologic oncology cancers. Focus is mainly on the use of laparoscopy for the treatment of Wilms' tumors but other neoplasms are also discussed.

RESULTS

We draw parallels with other similar pathologies, respecting critical lessons from international cooperative study groups. We discuss various aspects of the pros and cons of minimally invasive surgery in this patient population and make a case for the development of dedicated pediatric surgeons for urologic cancer.

CONCLUSION

Herein we draft a proposal suggesting a way forward with the adoption of reasonable paradigm shifts founded on carefully conducted studies for the introduction of minimally invasive surgery in the care of pediatric and adolescent urologic cancer.

Long-term follow-up of blood pressure and glomerular filtration rate in patients with a solitary functioning kidney: a comparison between Wilms tumor survivors and nephrectomy for other reasons

BACKGROUND

Children with unilateral Wilms tumor (WT) treated with chemotherapy and/or radiotherapy and nephrectomy have excellent survival rates. A solitary functioning kidney (SFK) is associated with progressive renal injury. This study aims to investigate the additional effect of Wilms tumor treatment on renal function compared with children with an SFK for non-oncological reasons.

METHODS

A single-center retrospective cohort study on the renal injury markers of 79 survivors of unilateral WT was performed and compared with a matched group of children with an SFK for non-oncological reasons. Mean age at follow-up was 12.4 (SD 5.9) years.

RESULTS

During follow-up, mean estimated glomerular filtration rate (eGFR) and blood pressure z-scores remained stable at an acceptable level. However, in the group of 31 WT patients with a follow-up of 15 years, 23% showed signs of renal injury. This proportion was smaller than the 54% in a group of SFK patients based on non-oncological causes (p = 0.004).

CONCLUSIONS

A significant proportion of WT survivors develop renal injury during follow-up. Our data may be an underestimation of the true frequency of progressive renal injury, due to a lack of information on proteinuria. As with patients with a non-oncological SFK, long-term follow-up is essential to monitor WT survivors.

Long-term renal function in unilateral non-syndromic renal tumor survivors treated according to International Society of Pediatric Oncology protocols

BACKGROUND

The risk of renal impairment among survivors of childhood unilateral non-syndromic renal tumors (RTs) is not well defined. We evaluated the prevalence of and possible risk factors for renal impairment by estimating Glomerular Filtration Rate (eGFR) categories and chronic kidney disease (CKD) according to Kidney Disease: Improving Global Outcomes guidelines.

PROCEDURE

Since 1978, 82 patients were treated for RT, according to the International Society of Pediatric Oncology protocols in a single oncology unit. Of the 67 survivors, those who underwent nephron sparing surgery, those with short-term follow-up or those who had bilateral and/or syndromic disease or a second malignancy were excluded. Thirty-five adult survivors (14 M/21F; mean age 25 years; mean follow-up 20 years) were studied by chemistry, kidney ultrasound, blood pressure measurement, urinanalysis. Correlations were investigated between the prevalence of eGFR categories and CKD and gender, age at diagnosis, radiotherapy, chemotherapy, body mass index, time of follow-up, and age at study.

RESULTS

Eight (22.9%) survivors presented a mildly decreased eGFR (G2 category), the mean value was 80 ± 9.78 ml/min/1.73m(2) (median 84.5, range 63-89). Three (8.6%) survivors had CKD and a fourth (2.9%) hypertension. No significant correlations between G2 category and clinical variables were found.

CONCLUSIONS

A small percentage of survivors had CKD or hypertension after two decades. It is not yet clear whether a mildly decreased eGFR that does not constitute CKD in the absence of other markers (albuminuria and/or kidney ultrasound abnormalities) is likely to progress to CKD. Health promotion programs to avoid comorbidities are required.

Renal function in patients with Wilms tumor

Survival in patients with Wilms tumor (WT) is excellent compared with other pediatric malignancies and adult renal tumors. Treatment-related long-term morbidity and mortality in WT survivors is an area of increasing concern. Renal dysfunction is an example of one of the most feared long-term issues observed in these survivors. Direct toxicity from chemotherapy and radiation as well as direct nephron ablation from surgical treatment (nephrectomy) renders the kidney susceptible to a multitude of problems over time in patients with WT. In this article, we review the existing literature pertaining to renal function in these patients. Incidence rates, causes, and methods to mitigate renal dysfunction are presented in 3 distinct clinical situations: sporadic unilateral WT, syndromic unilateral WT, and bilateral WT. We also offer a critical lens on the current role of nephron-sparing surgery as a means to preserve renal function in these patients. Finally, we discuss potential avenues for refining renal function preservation in patients with WT in the future. We conclude that: (1) renal function in pediatric cancer survivors must be carefully ascertained prospectively using methods that allow diagnosis of mild cases (rather than focus solely on extreme cases represented by the development of end-stage renal disease), (2) every effort should be made to recognize subtle features of predisposition syndromes to avoid syndromic cases from being misclassified and treated as sporadic, (3) molecular stratification for disease aggressiveness as well as multifocality and renal dysfunction will be very important to tailor treatment and balance survival with preservation of renal function, and (4) the role and potential benefits of nephron-sparing surgery deserves careful exploration under well-designed protocols.

Practice patterns and outcomes of pediatric partial nephrectomy in the United States: Comparison between pediatric urology and general pediatric surgery

BACKGROUND

In the United States, both pediatric urologists (PUROs) and general pediatric surgeons (GPSs) perform nephrectomies in children, with PUROs performing more nephrectomies overall, most commonly for benign causes. GPSs perform more nephrectomies for malignant causes. We questioned whether the same trends persisted for partial nephrectomy.

OBJECTIVE

We hypothesized that PUROs performed more partial nephrectomies for all causes, including malignancy. Our primary aim was to characterize the number of partial nephrectomies performed by PUROs and GPSs. We also compared short-term outcomes between subspecialties.

STUDY DESIGN

We analyzed the Pediatric Health Information System (PHIS), a database encompassing data from 44 children's hospitals. Patients were ≤18 years old and had a partial nephrectomy (ICD-9 procedure code 554) carried out by PUROs or GPSs between 1 January, 2004 and June 30, 2013. Queried data points included surgeon subspecialty, age, gender, 3M™ All Patient Refined Diagnosis Related Groups (3M™ APR DRG) code, severity level, mortality risk, length of stay (LOS), and medical/surgical complication flags. Data points were compared in patients on whom PUROs and GPSs had operated. Statistical analysis included the Student t test, chi-square test, analysis of covariance, and logistic regression.

RESULTS

Results are presented in the table. While PUROs performed the majority of partial nephrectomies, GPSs operated more commonly for malignancy. For surgeries performed for non-malignant indications, PURO patients had a shorter LOS and lower complication rate after controlling for statistically identified covariates. There was no difference in LOS or complication rate for patients with malignancy.

DISCUSSION

A Pediatric Health Information System study of pediatric nephrectomy demonstrated PUROs performed more nephrectomies overall, but GPSs performed more surgeries for malignancy. The difference was less dramatic for partial nephrectomies (63% GPS, 37% PURO) than for radical nephrectomies (90% GPS, 10% PURO). PUROs performed more partial nephrectomies for benign indications (94% PURO, 6% GPS) at an even greater rate than nephrectomies (88% PURO, 12% GPS). As a national database study, there are a number of inherent limitations: applicability of results to non-participating hospitals, possibility of inaccurate data entry/coding, and lack of data points that would be relevant to the study.

CONCLUSIONS

While most partial nephrectomies in the United States are performed by PUROs, GPSs perform the majority of surgeries for malignancy. There is no difference in LOS or complication rate undergoing nephron-sparing surgery for malignant disease; however, PUROs had a shorter LOS and lower complication rate when operating for benign diseases.

Laparoscopic Nephron-sparing Surgery for Metanephric Adenoma in Children: A Report of 2 Cases

Metanephric adenoma (MA) is an epithelial benign tumor of the kidney and very rare in children. Here we present 2 cases of MA treated by laparoscopic nephron-sparing surgery in children. To the best of our knowledge, we report the first cases of laparoscopic nephron-sparing surgery for MA in children.

Current surgical standards of care in Wilms tumor

BACKGROUND

Wilms tumor (WT) is the second most common abdominal tumor in children.

METHODS

This chapter discusses surgical considerations for the management of unilateral and bilateral WT.

RESULTS

Currently, survival exceeds 90%, owing to multicenter studies under the auspices of the Children's Oncology Group and Société Internationale d'Oncologie Pédiatrique. Surgical excision remains the mainstay of oncologic control and is also crucial for proper staging of disease in order to direct adjuvant therapy and limit treatment-related morbidity.

CONCLUSIONS

Careful attention must be paid to proper disease staging, upfront and adjuvant therapy, and surgical technique in order to optimize oncologic outcomes while minimizing short- and long-term morbidity.

A case of chromophobe renal cell carcinoma in a 12-year-old girl

Renal cell carcinoma (RCC) accounts for only 2-6 % of pediatric renal tumors. Chromophobe RCC is very rare in pediatric patients, with only a few cases reported. A 12-year-old girl who had abdominal and left flank pain visited the pediatric clinic of a local hospital. A uniformly enhanced tumor measuring 2.5 cm × 2.3 cm was found on computed tomography. On magnetic resonance imaging, T2-weighted images showed a solid tumor with hyperintensity suggesting intratumoral necrosis. We considered RCC and Wilms' tumor as differential diagnoses, but we could not reach a definitive diagnosis from the radiographic findings. We then performed right partial nephrectomy with regional lymph node dissection. The histopathological diagnosis was pT1aN0 chromophobe RCC. After the surgery, no recurrence has been observed for 15 months.

[Renal late effects in patients treated for cancer in childhood]

Impaired renal function may occur following multimodal treatment of cancer in childhood. Renal late effects caused by chemotherapy, renal surgery and/or radiotherapy are now well described; but little is known about their prevalence and time of development. Herein, we provide a synthesis of the different renal complications that may occur with their physiopathology in relation with specific treatment exposures. This review summarized the literature that supported the recommendations issued by the long-term follow-up group of the "Société française des cancers de l'enfant (SFCE)" for childhood cancer survivors at risk for nephrotoxicity (www.sfce.org ; www.soc-nephrologie.org/SNP/index.htm). We developed these monitoring elements and the lifestyle recommendations for all asymptomatic survivors.

Renal function in survivors of nonsyndromic Wilms tumor treated with unilateral radical nephrectomy

BACKGROUND

Partial nephrectomy is considered by some for children with unilateral Wilms tumor (UWT) to avoid the theoretical complication of renal insufficiency. In the current study, the authors evaluated the prevalence of hypertension and impaired renal function in long-term survivors of nonsyndromic UWT who were treated without nephrotoxic chemotherapy or ionizing radiation.

METHODS

Eligibility included age ≤15 years at the time of diagnosis of nonsyndromic UWT, treatment receipt before 2002, and maintenance of disease remission after unilateral nephrectomy without receipt of abdominal irradiation or nephrotoxic chemotherapy. Renal function was assessed by urinalysis and estimated glomerular filtration rate (eGFR). Patients receiving antihypertensive medication or those with blood pressure readings of >140/90 mm Hg were considered to be hypertensive.

RESULTS

A total of 75 patients with a median age at diagnosis of 3.2 years (range, 0.2-12.1 years) met eligibility criteria. The median length of follow-up was 19.6 years (range, 10.0-32.8 years). All but 1 patient had stage I/II disease. Sixty-eight patients (90.7%) patients had WT with favorable histology and 7 patients had anaplastic histology. Sixteen patients (21.3%) had an eGFR <90 mL/minute/1.73m(2), 2 of whom also had proteinuria (12.5%). No patient had an eGFR <60 mL/minute/1.73m(2). Five patients (6.7%) had hypertension, 3 of whom were receiving antihypertensive medications. At the time of last follow-up, no patient had developed end-stage renal disease.

CONCLUSIONS

Patients with UWT who were treated with unilateral radical nephrectomy without nephrotoxic chemotherapy or ionizing radiation appear to be at low risk of developing significant long-term renal dysfunction. For this patient population, the routine use of partial nephrectomy does not appear justified. However, monitoring and counseling are important for identifying the rare patient who develops subtle renal insufficiency and therefore might be at an increased risk of adverse cardiovascular sequelae.

NEPHRON-SPARING SURGERY FOR BILATERAL WILMS TUMOR

Synchronous bilateral disease occurs in approximately 5 % of children with Wilms tumor (WT), and is independently associated with an increased risk of renal insufficiency. Nephron-sparing surgery (NSS) allows preservation of renal mass and improved renal function. Published oncologic and functional outcomes with NSS to date are generally good, likely reflecting proper patient selection and excellent surgical technique during tumor excision, as well as appropriate use of upfront and adjuvant therapies. Here we highlight important issues regarding the use of NSS in children with bilateral Wilms tumor (BWT).