Partial nephrectomy for unilateral Wilms tumor: results of study SIOP 93-01/GPOH

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.

Wilms tumor in horseshoe kidney with extensive vascular thrombosis: A case report

INTRODUCTION AND IMPORTANCE

Wilms tumor (WT), a prevalent pediatric renal malignancy (7 %), frequently intertwines with genitourinary anomalies. This unique report presents a case of WT combined with horseshoe Kidney and an extending atrial thrombus, emphasizing critical management considerations.

CASE PRESENTATION

A 3-year-old boy, experiencing flank pain and weight loss, manifested a WT linked to horseshoe Kidney, accompanied by an atrial thrombus. Neoadjuvant chemotherapy downsized the tumor and thrombus, enabling successful surgical intervention. Post-surgery, 27 weeks of adjuvant chemotherapy were administered. Over three years, follow-up exhibited renal recovery, no recurrence, and clear CT scans.

DISCUSSION

Prompt identification, precise imaging (via CT angiography), and multidisciplinary care are pivotal for managing WT in horseshoe Kidney cases. Preoperative chemotherapy notably reduced tumor and thrombus sizes, enhancing surgical feasibility. Long-term vigilance is essential for recurrence and treatment-related complications.

CONCLUSION

Effectively managing WT in horseshoe Kidneys demands timely recognition, meticulous imaging, and collaborative management. Successful outcomes highlight preoperative chemotherapy's benefits and underscore extended monitoring's significance in confirming sustained recovery.

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.

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.

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.

Synchronous Bilateral Wilms Tumor: Five-Year Single-Center Experience with Assessment of Quality of Life

Context:

Synchronous Bilateral Wilms tumor (sBWT).

Aims:

This study aimed to assess the outcome of patients with sBWT treated on SIOP protocol.

Settings and Design:

Retrospective and prospective randomized study.

Subjects and Methods:

SIOP 93-01 protocol was used to study nine patients of sBWT in a single center and followed up over a period from 2 to 5 years.

Statistical Analysis Used:

Unpaired t-test and Mann–Whitney U-test were used for analysis.

Results:

Of nine patients, six were included in the study as three patients lost to follow-up. Among the six patients, there were four girls and two boys with a median age of 2 years. Mean regression in the size of tumor was 87% in four out of six patients. Tumor with unfavorable histology showed 32% response (ratio of favorable: unfavorable histology 2:1). Event-free survival rate was 81.3% and overall survival was 90% over 2–5 years. Recurrence was seen in two patients of whom one had Denys–Drash syndrome. Mean DTPA glomerular filtration rate was 91.4/ml/min/1.73 m² preoperatively and that of 3 months after completion of treatment was 84/ml/min/1.73 m². Health-related quality of life (HRQOL) using Pediatric Quality of Life Inventory and Lansky Play Performance Scale revealed significant improvement results of all functioning domains such as physical, social, emotional, and school subscales with P < 0.05 and performance scale (P < 0.04).

Conclusions:

We suggest SIOP protocol for sBWT and bilateral nephron-sparing surgery in two stages. However, long-term follow-up is required to assess the ultimate renal function outcome. HRQOL is an essential guide in improving the conditions of pediatric cancer survivors.

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.

Nephron-sparing surgery for Wilms tumor: A systematic review

INTRODUCTION

Radical nephrectomy (RN, or total nephrectomy) is the current gold-standard surgical treatment for children with Wilms tumors (WT). However, nephron-sparing surgery (NSS, or partial nephrectomy) has recently been gaining increasing attention. The objective of this systematic review is to compare the effectiveness of NSS as compared with RN for the treatment of children with WT.

METHODS

We searched the Cochrane Controlled Trials Register, clinicaltrials.gov, MEDLINE, EMBASE, Google Scholar, and recently presented meeting abstracts for reports in English. The bibliographies of included studies were then hand-searched for any missed articles. The protocol was prospectively registered. Manuscripts were assessed and data abstracted in duplicate with differences resolved by the senior author. Owing to high heterogeneity among the final included studies, only a qualitative systematic review was performed; no formal meta-analysis was undertaken.

RESULTS

We identified 694 articles, 118 of which were selected for full-text review and 66 of which were included in the final analysis. Most studies were single- or multi-institution retrospective case series (60, 91%), with a small number of prospective cohort studies (6, 9%) and 1 administrative database analysis. Most studies were from Europe (27, 41%) or North America (21, 32%). Nearly half (32, 48%) of studies those were included were dated from 2010 or later. In total, data on 4,002 patients were included, of whom 1,040 (26%) underwent NSS and 2,962 (74%) underwent NSS. Reported rupture rates were similar between RN and NSS (13% vs. 7%), as were recurrence rates (12% vs. 11%) and survival rates (85% vs. 88%). However, these comparisons are limited by inherent biases in the design and reporting of most included studies.

CONCLUSIONS

Most contemporary studies reporting the use of NSS in children with WT report similar long-term outcomes to RN. However, most existing studies are limited by their small numbers, inconsistent reporting, and methodological biases. There are significant opportunities for future research on the use of NSS in children with WT, including issues related to surgical quality, optimal technique, timing and duration of chemotherapy, and variation in the use of NSS among centers.

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.

Nephron sparing surgery (NSS) for unilateral wilms tumor (UWT): the SIOP 2001 experience

BACKGROUND

Total nephrectomy (TN) remains the standard treatment of unilateral Wilms tumors (uWT). The SIOP WT-2001 protocol allowed Nephron Sparing Surgery (NSS) for polar or peripherally non-infiltrating tumors.

AIM

Inventory of the current SIOP NSS-experience.

PROCEDURES

2,800 patients with a unilateral, localized or metastatic and an unequivocal surgical technique recorded were included. All had neo-adjuvant chemotherapy and delayed surgery. In 91 (3%) NSS was performed and in 2709 TN. Data was retrieved from the SIOP WT 2001 database.

RESULTS

NSS group contained 65% stage I tumours and the TN group 48%. Tumor volume (at diagnosis and surgery) was significantly smaller in the NSS group. Within stage III, after NSS, 7/12 (58%) had positive margins (M +), 5 with tumor negative lymph nodes (LN-). After TN, 355/712 (55%) had M + , 182 were LN-. Treatment of M+ in the NSS group resulted in two conversions to TN (one combined with radiotherapy), three patients had radiotherapy only and in two patients local therapy, if given, was not recorded. After NSS, four recurrences occurred. For localized disease the 5-year overall (OS) and event free survival (EFS) in NSS group was 100 and 94.8 (95% CI:89.9-99.9), respectively, while OS and EFS in the TN group were 94.4 (95% CI: 93.2-95.5, log-rank test P = 0.06) and 86.5 (95% CI:85.0-88.1, log-rank test P = 0.06), respectively.

CONCLUSIONS

NSS was only performed in 3% of patients with uWT. Despite excellent survival with few relapses, the gain of nephrons needs to be weighed against the risk to induce stage III with intensified therapy.

Innovations in the management of Wilms' tumor

Advances in the management of Wilms' tumor have been dramatic over the past half century, not in small part due to the institution of multimodal therapy and the formation of collaborative study groups. While different opinions exist in the management of Wilms' tumors depending on where one lives and practices, survival rates have surpassed 90% across the board in Western societies. With more children surviving into adulthood, the concerns about morbidity have reached the forefront and now represent as much a consideration as oncologic outcomes these days. Innovations in treatment are on the horizon in the form of potential tumor markers, molecular biological means of testing for chemotherapeutic responsiveness, and advances in the delivery of chemotherapy for recurrent or recalcitrant tumors. Other technological innovations are being applied to childhood renal tumors, such as minimally invasive and nephron-sparing approaches. Risk stratification also allows for children to forego potentially unnecessary treatments and their associated morbidities. Wilms' tumor stands as a great example of the gains that can be made through protocol-driven therapy with strenuous outcomes analyses. These gains continue to spark interest in minimization of morbidity, while avoiding any compromise in oncologic efficacy. While excitement and innovation are important in the advancement of treatment delivery, we must continue to temper this enthusiasm and carefully evaluate options in order to continue to provide the highest standard of care in the management of this now highly curable disease.

Variation in use of nephron-sparing surgery among children with renal tumors

OBJECTIVE

Given the negative long-term effects of renal insufficiency, nephron-sparing surgery (NSS) is increasingly discussed for the treatment of pediatric renal tumors. We sought to examine variation in practice patterns of NSS among children with renal tumors.

MATERIALS AND METHODS

We performed a retrospective cohort analysis of claims data for pediatric inpatient admissions captured by the Kids Inpatient Database (1997-2009). We identified children with renal tumors who underwent surgery, including radical nephrectomy (RN) and NSS. We used multivariable logistic regression to assess the relationship between use of NSS and various clinical, demographic, and geographic predictors of interest.

RESULTS

We identified 10,108 pediatric inpatient admissions for renal tumors. Of these, 1657 were surgical admissions, with 1501 patients (90.5%) undergoing RN and 156 (9.5%) undergoing NSS. On multivariable analysis, NSS was associated only with a concomitant diagnosis of renal insufficiency (relative ratio [RR] 3.37, p = 0.01) and surgery in the Northeastern USA (RR 3.07, p = 0.03). Race/ethnicity, age, payer type, procedure year, and other non-clinical factors were not significantly associated with NSS.

CONCLUSION

In a large, nationwide pediatric cohort, RN remains the most common surgical intervention for renal tumors. NSS is significantly associated with a diagnosis of renal insufficiency, but not non-clinical factors such as patient gender or race. © 2014 Published by Elsevier Ltd on behalf of Journal of Pediatric Urology Company.

Laparoscopic treatment of renal cancer in children: a multicentric study and review of oncologic and surgical complications

OBJECTIVE

The aim was to report a multicentric study with a longer follow-up to evaluate the laparoscopic radical nephrectomy in children with renal cancer.

MATERIAL AND METHODS

This was a retrospective multicentric study, from October 2005 to January 2012, of children who underwent a laparoscopic radical nephrectomy for small renal malignant tumors.

RESULTS

Seventeen children were included in this study. Sixteen underwent chemotherapy before surgery according the SIOP (Société Internationale d'Oncologie Pédiatrique) protocol and one was treated by surgery only for a carcinoma. All except one could be treated by laparoscopy; the biggest tumoral size was 8 cm. The median hospital stay was 3 days (2-10). The pathologic examination showed 15 Wilms' tumors, one clear cell sarcoma and one TFE3 renal cell carcinoma. With a median follow-up of 42 months (range 12 and 77 months) after laparoscopic radical nephrectomy, 15 children had no oncological complications (port site or local recurrence, pulmonary metastasis) and one had a local recurrence without intraoperative tumoral rupture. The child with TFE3 renal cell carcinoma died 4 years after surgery from brain and lung metastases without local recurrence. No small bowel obstruction occurred.

CONCLUSIONS

Radical nephrectomy in children for Wilms' tumor or other renal cancer can be safely performed laparoscopically and our indications can be summarized, for trained laparoscopic surgeons, by small tumors under about 8 cm diameter, especially without crossing the lateral edge of the vertebra on the CT scan at the time of surgery.

Use of nephron sparing surgery and impact on survival in children with Wilms tumor: a SEER analysis

PURPOSE

Nephron sparing surgery is the standard of care for many adults with renal tumors and has been described in some children with Wilms tumor. However, beyond case series the data concerning nephron sparing surgery application and outcomes in patients with Wilms tumor are scarce. We examined nephron sparing surgery outcomes and factors associated with its application in children with Wilms tumor.

MATERIALS AND METHODS

We retrospectively reviewed the 1998 to 2010 SEER database. We identified patients 18 years old or younger with Wilms tumor. Clinical, demographic and socioeconomic data were abstracted, and statistical analysis was performed using multivariate logistic regression (predicting use of nephron sparing surgery limited to unilateral tumors smaller than 15 cm) and Cox regression (predicting overall survival) models.

RESULTS

We identified 876 boys and 956 girls with Wilms tumor (mean ± SD age 3.3 ± 2.9 years). Of these patients 114 (6.2%) underwent nephron sparing surgery (unilateral Wilms tumor in 74 and bilateral in 37). Median followup was 7.1 years. Regarding procedure choice, nephron sparing surgery was associated with unknown lymph node status (Nx vs N0, p <0.001) and smaller tumor size (p <0.001). Regarding survival, only age (HR 1.09, p = 0.002), race (HR 2.48, p = 0.002), stage (HR 2.99, p <0.001) and lymph node status (HR 2.17, p = 0.001) predicted decreased overall survival. Survival was not significantly different between children undergoing nephron sparing surgery and radical nephrectomy (HR 0.79, p = 0.58).

CONCLUSIONS

In children with Wilms tumor included in the SEER database nephron sparing surgery has been infrequently performed. Nephron sparing surgery application is associated with smaller, bilateral tumors and with omission of lymphadenectomy. However, there are no evident differences in application of nephron sparing surgery based on demographic or socioeconomic factors. Despite lymph node under staging, overall survival is similar between patients undergoing nephron sparing surgery and radical nephrectomy.

Nephron sparing surgery for unilateral non-syndromic wilms tumor

The initial therapy for most children with Wilms tumor is radical nephrectomy. Several centers, have explored the role of Nephron-sparing procedures in children with unilateral non-syndromic Wilms tumors. The primary motivation for this approach is concern about late occurrence of renal dysfunction after unilateral nephrectomy. We report our experience with NSS for unilateral non-syndromic Wilms tumor. We reviewed the records of nine children who underwent nephron sparing surgery for unilateral, nonsyndromic Wilms tumors at our Hospital between Jan 2000 through Jan 2012. All patients received preoperative chemotherapy with two drugs (vincristine, and dactinomycin) following which patients underwent tumor resection. Subsequent renal function was assessed by estimating the glomerular filtration rate using creatinine clearance and other measures of long-term renal function assessment included blood pressure evaluation and the need for antihypertensive medications. During the study period nine children with a mean age 19.66 ± 14.37 months at diagnosis and presenting with unilateral non-syndromic Wilms tumor underwent nephron sparing surgery. In all the nine children, the renal plane of resection showed a tumor-free margin. Post-operative serum creatinine repeated at the end of 3 months revealed maintenance of good renal function in all children. Nephron sparing surgery is a safe and effective option in the management of early stage unilateral non-syndromic Wilms tumor. It is oncologically safe and does not lead to decreased local tumor control. The function of the kidney remnant remains rather well.

Image based feasibility of renal sparing surgery for very low risk unilateral Wilms tumors: a report from the Children's Oncology Group

PURPOSE

Nephrectomy with lymph node sampling is the recommended treatment for children with unilateral Wilms tumor under the Children's Oncology Group protocols. Using radiological assessment, we determined the feasibility of performing partial nephrectomy in a select group of patients with very low risk unilateral Wilms tumor.

MATERIALS AND METHODS

We reviewed imaging studies of 60 patients with a mean age of less than 2 years with very low risk unilateral Wilms tumor (mean weight less than 550 gm) to assess the feasibility of partial nephrectomy. We evaluated percentage of salvageable parenchyma, tumor location and anatomical features preventing a nephron sparing approach.

RESULTS

A linear relationship exists between tumor weight and computerized tomography estimated tumor volume. Mean tumor weight in the study population was 315 gm. Partial nephrectomy was deemed feasible in only 5 of 60 patients (8%).

CONCLUSIONS

When considering a select population with very low risk unilateral Wilms tumor (lower volume tumor), only a small percentage of nonpretreated patients are candidates for nephron sparing surgery.

Oncology: the role of partial nephrectomy in Wilms tumor

Wilms tumor represents the most common pediatric renal malignancy and the fourth most common childhood cancer overall. Overall survival from Wilms tumor has increased to over 90 % secondary to multidisciplinary therapy and multi-institutional cooperative group trials. Recent therapeutic focus has shifted to reduction in treatment morbidity and renal preservation while maintaining the high survival rates. Partial nephrectomy is an integral component of the multimodal treatment protocols for Wilms tumor patients with bilateral disease, solitary kidney, or predisposing syndromes. Recent consideration has been given to utilization of nephron sparing surgery (NSS) in carefully selected patients with nonsyndromic unilateral Wilms tumor. While long-term, prospective data in this subgroup of patients is not yet available, case series demonstrate comparable oncologic outcomes after partial versus radical nephrectomy. The relative rarity of Wilms tumor, especially those amenable to upfront partial nephrectomy, presents a challenge to conducting controlled trials.

Therapeutic results in stage I Wilms' tumors in children - 15 years of surgical experience

INTRODUCTION

Progress in the therapeutic management of Wilms' tumors (WT) in children has resulted in the fact that presently, almost all children with stage I and favorable histology diseases have a chance for a cure.

THE AIM OF THE STUDY

The objective of the report is an analysis of therapeutic results in children with unilateral stage I Wilms' tumors depending on the extent of tumor resection.

MATERIAL AND METHODS

The analysis included children treated between 1993 and 2008 under the Polish Wilms' Tumor Study, initially following the protocol SIOP 93-01 (patients treated up to 2002) and subsequently SIOP 2001. Following neoadjuvant chemotherapy, depending on tumor size and tumor response to treatment, the children were qualified for a radical nephrectomy, simple nephrectomy, or nephron-sparing surgery. Following surgical treatment, all the children were subjected to adjuvant chemotherapy in keeping with the therapeutic protocol obligatory at the time.

RESULTS

Within the 15 years, 111 children with Wilms' tumor were treated; the group included 43 children with stage I disease, which constituted 38.9% of the total number. Radical nephrectomies were performed in three (6.98%) children, simple nephrectomies in 32 (74.42%), and nephron-sparing surgery in eight (18.6%). Regardless of the employed surgical treatment modality, all the children are alive and none have demonstrated recurrent disease. The mean post-treatment completion follow-up period is 73 months (median value, 68 months).

CONCLUSION

A simple nephrectomy and, whenever possible, nephron-sparing surgery represents sufficient treatment in 93% of children with stage I Wilms' tumor. To improve qualification for surgical treatment we propose the employment of NSS for stage Ia Wilms' tumors and SN for stage Ib Wilms' tumors.

Pathological review of Wilms tumor nephrectomy specimens and potential implications for nephron sparing surgery in Wilms tumor

PURPOSE

Nephron sparing surgery is accepted as standard of care for children with bilateral Wilms tumor or Wilms tumor in a solitary kidney and some study protocols allow nephron sparing surgery in select cases of unilateral Wilms tumor. With the increasing use of nephron sparing surgery in Wilms tumor, we reviewed pathological features from Wilms tumor radical nephrectomy specimens to determine the potential efficacy of a nephron sparing approach.

MATERIALS AND METHODS

Medical records of children undergoing pre-chemotherapy radical nephrectomy for unilateral Wilms tumor at our institution were reviewed. Ideal candidates for nephron sparing surgery were defined as those having a unifocal mass outside the renal hilum, sparing a third or more of the kidney, favorable histology, no signs of renal sinus or segmental vascular invasion, no metastatic lymph nodes or gross regional disease, and a distinct interface on pathological review between tumor and remaining parenchyma.

RESULTS

A total of 78 children at a median age of 3.2 years (range 0.3 to 16.2) underwent pre-chemotherapy radical nephrectomy for unilateral Wilms tumor. Median tumor diameter was 11 cm (range 2.5 to 22). Of these children 36 (46.2%) had tumors sparing a third or more of the kidney and 70 (89.7%) had unifocal tumors. There were 73 specimens (94.6%) that showed favorable histology, and 56 (71.8%) of the specimens had a distinct border between tumor and remaining parenchyma. In total, 19 (24.4%) of the patients reviewed met all of our strict pathological criteria as ideal partial nephrectomy candidates.

CONCLUSIONS

In a post hoc analysis using strict pathological criteria and accepted surgical oncologic principles, as many as 1 in 4 children undergoing pre-chemotherapy surgery for nonmetastatic, unilateral Wilms tumor have post-resection pathological tumor characteristics favorable for nephron sparing surgery.

Oncologic outcomes of partial versus radical nephrectomy for unilateral Wilms tumor

BACKGROUND

Radical nephrectomy (RN) is the recommended surgical management as part of multi-modality therapy for unilateral Wilms tumor (UWT). Based on recent data demonstrating that renal preserving surgery decreases the likelihood of chronic renal disease and associated co-morbidities, we analyzed oncologic outcomes of patients after partial nephrectomy (PN) for UWT.

METHODS

We identified all published cases of PN for UWT. Cases of elective PN for UWT were analyzed for tumor stage, presence, timing and location of disease recurrence, and overall survival (OS). Eighty-two patients had adequate data for analysis. For comparison, these endpoints were collected on consecutive children undergoing RN for UWT from 1985 to 2010 at our institution.

RESULTS

Of the 82 PN patients, tumor stage was: I-64, II-10, III-6, IV-2. Of the 121 RN patients, the staging was: I-24, II-45, III-29, IV-23. In the PN group, at a median of 48 months (3-372), the recurrence-free survival (RFS), local RFS and OS were 89.1%, 92.7%, and 95.1%, respectively. In the RN group, at a median of 69 months (0-214), the RFS, local RFS, and OS were 83.1%, 95.0%, and 95.0%, respectively. After controlling for stage, there were no statistically significant differences in the above oncologic outcomes between the groups.

CONCLUSION

Based on reported data, the oncologic outcomes of PN for UWT in selected patients do not appear to differ from those of RN. PN for appropriately selected patients with UWT should be studied in prospective, co-operative group trials.

Wilms' tumor- roadmaps of management

The management of Wilms' tumor emerging of the outstanding clinical trials undertaken in the developed world in the last four decades has led to excellent longterm outcomes. The scenario in developing country like India is different; late presentation with massive tumors and advanced stage, lacunae in staging, nonavailability of pediatric medical oncologists and poor follow-ups are common. A comprehensive summary of available therapeutic modalities is provided here along with clear roadmaps of management of Wilms' tumor as per Société Internationale d'Oncologie Pédiatrique (SIOP) and National Wilms' Tumor Study Group/Children's Oncology Group (NWTSG/COG) protocols in simple tabulated form.

Wilms tumor

Significant improvement has been made in the treatment of children with Wilms tumor. New protocols are in place designed to maintain a high rate of cure for these patients while minimizing toxicity, based on refinement of the risk-stratification system.

Contemporary use of nephron-sparing surgery for children with malignant renal tumors at freestanding children's hospitals

OBJECTIVE

It is widely accepted that, when feasible, nephron-sparing surgery (NSS) is preferable to radical nephrectomy (RN) for treatment of renal tumors in adults. However, RN is more frequently used in children. We sought to compare in-hospital outcomes after NSS and RN for malignant pediatric renal tumors.

MATERIAL AND METHODS

The pediatric health information system (PHIS) combines data from more than 40 North American pediatric hospitals. We queried PHIS to identify children with malignant renal tumors who underwent surgery from 2003 to 2009. We examined whether outcomes (complication rates, cost, and length of stay) differed by procedure type. Multivariate regression models were used to adjust for confounding, and generalized estimating equations were used to adjust for hospital clustering.

RESULTS

We identified 1235 children with renal tumors who underwent RN (91%) or NSS (9%). Patients undergoing RN and NSS had similar median comorbidity scores (P = .98), hospital lengths of stay (each 6.0 days, P = .54), in-hospital charges, ($25,700 vs $37,000, P = .11), and surgical complication rates (16.4 vs 20.5%, P = .24). These outcomes remained similar after adjusting for other patient and hospital factors.

CONCLUSIONS

Most children with malignant renal tumors treated at children's hospitals undergo RN. RN and NSS use were not significantly different in terms of their length of hospital stay, in-hospital charges, and complication rates. Although oncological outcomes are lacking, these data suggest that NSS may be performed in selected children with malignant renal tumors without significantly increasing their hospital charges, length of stay, or surgical complication rates.

Risk factors for end stage renal disease in non-WT1-syndromic Wilms tumor

PURPOSE

We assessed risk factors for end stage renal disease in patients with Wilms tumor without known WT1 related syndromes. We hypothesized that patients with characteristics suggestive of a WT1 etiology (early onset, stromal predominant histology, intralobar nephrogenic rests) would have a higher risk of end stage renal disease due to chronic renal failure. We predicted a high risk of end stage renal disease due to progressive bilateral Wilms tumor in patients with metachronous bilateral disease.

MATERIALS AND METHODS

End stage renal disease was ascertained in 100 of 7,950 nonsyndromic patients enrolled in a National Wilms Tumor Study during 1969 to 2002. Risk factors were evaluated with cumulative incidence curves and proportional hazard regressions.

RESULTS

The cumulative incidence of end stage renal disease due to chronic renal failure 20 years after Wilms tumor diagnosis was 0.7%. For end stage renal disease due to progressive bilateral Wilms tumor the incidence was 4.0% at 3 years after diagnosis in patients with synchronous bilateral Wilms tumor and 19.3% in those with metachronous bilateral Wilms tumor. For end stage renal disease due to chronic renal failure stromal predominant histology had a HR of 6.4 relative to mixed (95% CI 3.4, 11.9; p<0.001), intralobar rests had a HR of 5.9 relative to no rests (95% CI 2.0, 17.3; p=0.001), and Wilms tumor diagnosis at less than 24 months had a HR of 1.7 relative to 24 to 48 months and 2.8 relative to greater than 48 months (p=0.003 for trend).

CONCLUSIONS

Metachronous bilateral Wilms tumor is associated with high rates of end stage renal disease due to surgery for progressive Wilms tumor. Characteristics associated with a WT1 etiology markedly increased the risk of end stage renal disease due to chronic renal failure despite the low risk in non-WT1 syndromic cases overall.

Current management of wilms' tumor

Wilms' tumor is the most common malignant renal tumor in children. Survival has improved dramatically over time as a result of prospective randomized clinical trials conducted by the pediatric cooperative cancer groups. Current research is directed toward identifying low-risk patients for whom a reduction in treatment intensity would decrease long-term morbidity. This article reviews the most recent advances in the biology and treatment of children with Wilms' tumor.

Pediatric urologic oncology: organ-sparing surgery in kidney and testis

Technological advances in imaging as well as increased knowledge of tumor-specific biology have promoted the role of organ-sparing approaches to pediatric renal and testicular tumors. Application of these techniques continues to evolve as data on long-term follow-up become available and as protocol-guided investigation provides answers to therapeutic outcomes of these approaches. Optimally, organ-sparing surgery will continue to provide increased potential for preservation of both renal function and fertility.

Wilms' tumor

PURPOSE OF REVIEW

Wilms' tumor accounts for nearly 6% of all pediatric cancers and more than 95% of all kidney tumors in children. Fortunately, survival for patients with Wilms' tumor is generally excellent. This review will outline the results of prior clinical trials that have led to this excellent outcome and how information gleaned from these trials has led to the development of the current series of clinical trials for the management of children with Wilms' tumor.

RECENT FINDINGS

Tumor stage and histologic subtype have long been recognized as important prognostic factors in Wilms' tumor. More recent evidence suggests that, in certain instances, patient age, tumor size, response to therapy, and genetic abnormalities, specifically the loss of genetic material on chromosomes 1p and 16q, provide additional prognostic information. These factors have, therefore, been incorporated into a new risk stratification system that is currently being used to assign patients with Wilms' tumor to specific protocol-based therapies.

SUMMARY

Survival for patients with Wilms' tumor when considered as a whole, once less than 30%, is currently greater than 90%, with this dramatic improvement being due, in part, to the systematic manner in which the approach to therapy has evolved. Further refinement in therapy is being undertaken, with the current trials aiming to maintain the excellent survival for children being treated for Wilms' tumor, while minimizing therapy-related toxicity.

Renal tumours of childhood: an update

The role of the pathologist has been fundamental in the progress of the treatment of paediatric renal tumours. There are different philosophies in the treatment of these tumours, and there have been many recent advances in the areas of chemotherapy, identification of new entities, prognostic histological criteria following treatment and molecular prognostic and diagnostic features. This review discusses the different approaches of the different treatment protocols from Europe and North America, and reviews staging criteria, prognostic criteria and also the different tumour entities.

Role of MRI in the management of patients with nephroblastoma

Magnetic resonance imaging (MRI) presents the main diagnostic tool for differentiation and staging of renal tumors in childhood. Nephroblastoma is the most common malignant tumor in children. Radiological findings play an important role in therapy study trials of SIOP (International Society of Pediatric Oncology), especially for indicating preoperative chemotherapy. In the past few years MRI has gained great importance in imaging of nephroblastoma and has replaced computed tomography (CT). The aim of this review is to present the diagnostic possibilities of MRI in relation to the requirements of therapy studies. For nephroblastoma, MRI provides important information about tumor extent and distant metastasis. A special focus of MRI in distant staging is venous extent of the tumor into the inferior vena cava. In addition, MRI has an important role in monitoring chemotherapy and in preoperative planning by volume rendering and three-dimensional postprocessing.

Wilms tumour: prognostic factors, staging, therapy and late effects

Wilms tumour is the most common malignant renal tumour in children. Dramatic improvements in survival have occurred as the result of advances in anaesthetic and surgical management, irradiation and chemotherapy. Current therapies are based on trials and studies primarily conducted by large multi-institutional cooperatives including the Société Internationale d'Oncologie Pédiatrique (SIOP) and the Children's Oncology Group (COG). The primary goals are to treat patients according to well-defined risk groups in order to achieve the highest cure rates, to decrease the frequency and intensity of acute and late toxicity and to minimize the cost of therapy. The SIOP trials and studies largely focus on the issue of preoperative therapy, whereas the COG trials and studies start with primary surgery. This paper reviews prognostic factors and staging systems for Wilms tumour and its current treatment with surgery and chemotherapy. Surgery remains a crucial part of treatment for nephroblastoma, providing local primary tumour control and adequate staging and possibly controlling the metastatic spread and central vascular extension of the disease. Partial nephrectomy, when technically feasible, seems reasonable not only in those with bilateral disease but also in those with unilateral disease where the patient has urological disorders or syndromes predisposing to malignancy. Partial nephrectomy, however, is frequently not sufficient for an anaplastic variant of tumour. The late effects for Wilms tumour and its treatment are also reviewed. The treatment of Wilms tumour has been a success story, and currently in excess of 80% of children diagnosed with Wilms tumour can look forward to long-term survival, with less than 20% experiencing serious morbidity at 20 years from diagnosis. The late complications are a consequence of the type and intensity of treatment required, which in turn reflects the nature and extent of the original tumour. Continual international trial development and participation will improve matching of treatment needs with prognosis, reducing long-term complications in the majority. The advent of molecular markers of disease severity and improved functional imaging might help.

Indications for nephrectomy in children: what has changed?

OBJECTIVE

To review the indications for nephrectomy in children between 1990 and 2001, at the Starship Children's Hospital, Auckland, New Zealand.

PATIENTS AND METHODS

There were 206 nephrectomies. A retrospective review of the patients' notes was performed. The 12-year period was divided into two halves (1990-1996 and 1996-2001) which were then compared.

RESULTS

The total number of nephrectomies per year significantly increased over the period of the study (11.5 and 22.2 per year for 1990-1995 and 1996-2001, respectively; P<0.05), as did the number of partial nephrectomies (one and 23 for 1990-1995 and 1996-2001, respectively; P<0.01). Multicystic dysplastic kidney (MCDK), Wilms' tumour and vesico-ureteric reflux (VUR) accounted for more than half of the nephrectomies (60% and 68% for 1990-1995 and 1996-2001, respectively). The proportion of nephrectomies performed for these indications did not change (MCDK 25% and 34%, Wilms' 25% and 18%, VUR 16% and 18%, for 1990-1995 and 1996-2001, respectively), but fewer nephrectomies were performed for pelvi-ureteric junction (PUJ) obstruction in the second half of the study period (13% and 4% for 1990-1995 and 1996-2001, respectively; P<0.05).

CONCLUSION

The total number of nephrectomies, including partial nephrectomies, has increased significantly. The decrease in nephrectomies for PUJ obstruction could be accounted for by a more aggressive approach in the management and follow up of prenatally diagnosed hydronephrosis. Of note is that there was no significant change in the proportion of nephrectomies performed for Wilms' tumour, MCDK and VUR.

[Childhood kidney tumors -- the relevance of imaging]

Kidney tumors represent 6.2% of malignant tumors in children. History, clinical course and radiological findings are necessary elements in the differential diagnosis of the different renal tumors. In the case of nephroblastoma, chemotherapy is based solely on the radiological diagnosis without prior histology. In therapy-optimizing studies of the Society of Pediatric Oncology and Hematology, preoperative chemotherapy is performed. Therapy monitoring is performed in the course of and after preoperative chemotherapy to verify tumor response. Radiological staging plays a significant role in deciding on further treatment and in operative planning. Three-dimensional visualization of the abdominal situs can assist preoperative planning. In summary, diagnostic imaging in renal tumors in children plays a role in differential diagnosis, staging, monitoring of therapy, and surgical planning.

Predictors of surgical outcome in Wilms' tumor: a single-institution comparative experience

BACKGROUND

The merits of primary nephrectomy (PN) vs preoperative chemotherapy (PC) for patients with Wilms' tumor (WT) are much debated. Early data from the International Society of Pediatric Oncology suggested decreased intraoperative spillage but increased risk of local recurrence after PC. Patients with WT at our institution were managed with PC until 1996; subsequently, they underwent PN. This study compares these approaches as they affect tumor spillage, local recurrence, and survival.

METHODS

Patients with WT diagnosed at the Hospital for Sick Children from 1985 to 2003 were reviewed.

RESULTS

One hundred sixty patients were identified (114 PC and 46 PN). Tumor spill occurred in 6 (5.3%) of 114 PC and 2 (4.3%) of 46 PN patients. Tumor inhomogeneity, tumor size, and inferior vena cava compression/clot at diagnosis did not affect incidence of spill. Of 6 PC patients with surgical spill, 1 (17%) had significant tumor shrinkage, compared with 87 (81%) of 108 without spill (P < .001). Preoperative chemotherapy and PN had equal rates of surgical complications. Preoperative chemotherapy resulted in 12 (10.5%) of 114 local recurrences vs 5 (10.8%) of 46 with PN. Event-free survival and overall survival were 80% and 92% for PC at 129 months vs 85% and 96% for PN at 61 months.

CONCLUSIONS

Preoperative chemotherapy and PN are equally effective in the treatment of WT with no difference in tumor spillage. Failure of the tumor to shrink in size with PC was significantly associated with an increase in tumor spillage and would suggest that a more cautious surgical approach be undertaken in these cases.

Nephron-sparing surgery in children with primary renal tumor: indications and results

Nephron-sparing surgery (NSS) is the treatment of choice for children with bilateral Wilms' tumor (WT), or with WT on a single kidney, or with WT and a disease of the contralateral kidney, or with benign kidney tumor. NSS is a reasonable alternative to nephrectomy in children at risk of metachronous WT, including children with genetic syndromes, children younger than 1 year of age, and children with hyperplastic nephroblastomatosis. The use of NSS in selected children with "low-risk" or stage I "intermediate-risk" WT and a normal contralateral kidney is still controversial. Available data suggest that, in children with WT, NSS does not impair the outcome and has a renal function advantage over nephrectomy.

Wilms’ tumor management

PURPOSE OF REVIEW

The management of Wilms' tumor continues to evolve with two different approaches being taken by the National Wilms Tumor Study in North America and the International Society of Pediatric Oncology in Europe in regards to preoperative chemotherapy. Limiting the duration, dosage, and number of chemotherapeutic agents and the dosage of radiotherapy are common goals in both trials.

RECENT FINDINGS

Contralateral exploration of unilateral tumors will no longer be recommended in future National Wilms Tumor Studies. Percutaneous biopsy for tissue diagnosis is quite accurate, but there are concerning complications with its use. Partial nephrectomy is successful for low risk unilateral Wilms tumor, but its indications remain controversial. The surgical complication rate was similar between the National Wilms Tumor Study and the International Society of Pediatric Oncology, but intraoperative tumor spill was higher in the North American trials. Doxorubicin decreased the risk of recurrence in stage III tumors by 50%, and its current dose is not associated with late congestive heart failure. For selected patients, shorter courses of vincristine/dactinomycin or vincristine alone show equivalent results compared to current regimens. A longer course of chemotherapy (including doxorubicin) for clear cell sarcoma improves recurrence-free survival. Patients with Wilms' tumor, aniridia, major genitourinary malformations, and mental retardation, the WAGR syndrome, have a 50% chance of unexplained end-stage renal disease 20 years after treatment.

SUMMARY

Less aggressive means of diagnosis and treatment for Wilms' tumor are continuing to achieve very good cure rates while lowering long term morbidity for low risk patients. High-risk patients with unfavorable histology or the WAGR syndrome benefit from more intensive treatment and long-term follow-up.