Oncologic outcomes of partial versus radical nephrectomy for 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.

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.

Duplex kidney complicated with preoperative inferior nephroblastoma rupture in children: a case report and literature review

Background

We admitted a child with a duplex kidney combined with preoperative rupture of nephroblastoma and used this case to discuss the clinical features and treatment of this disease.

Case presentation

We retrospectively analyzed the clinical data of a 5-year-old girl with preoperative duplex kidney rupture combined with inferior nephroblastoma who was admitted to the Fourth Hospital of Baotou. In addition, we reviewed the relevant literature. The patient’s details were as follows: weight, 17 kg; height, 108 cm; and body surface area, 0.7 m². Abdominal ultrasound for abdominal pain revealed the presence of a left-sided renal mass; enhanced abdominal computed tomography further confirmed it to be a left-sided duplex kidney measuring approximately 6 × 5 × 5 cm, with a rupture originating from the lower kidney. The PubMed database was searched from 2010 to 2020 for the terms “Wilms’ tumor” and “Duplex” and “Wilms’ tumor” and “Rupture.” The treatment plan was preoperative chemotherapy (vincristine/dactinomycin, VA regimen) + left kidney tumor radical surgery + postoperative chemotherapy (actinomycin-D/VCR/doxorubicin, AVD regimen). Postoperative pathology revealed an International Society of Pediatric Oncology intermediate-risk stage-3 nephroblastoma (mixed type) in the left kidney. Literature review was performed with 71 cases meeting the set criteria with an aim to analyze and summarize the clinical characteristics and treatment of patients with ruptured nephroblastoma and duplex kidney combined with nephroblastoma.

Conclusions

To our knowledge, no previous studies have reported preoperative duplex kidney combined with nephroblastoma rupture. In patients with this condition, preoperative chemotherapy is recommended when the vital signs are stable and tumor resection can be performed after the tumor has shrunk to prevent secondary spread. If the patient’s vital signs are unstable, emergency exploratory surgery is needed. If the nephroblastoma rupture is old and limited, surgery can be performed when the tumor size is small.

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.

Wilms tumor: a review of current surgical controversies

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

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.

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.

[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.

Partial nephrectomy versus radical nephrectomy for clinical localised renal masses

BACKGROUND

Partial nephrectomy and radical nephrectomy are the relevant surgical therapy options for localised renal cell carcinoma. However, debate regarding the effects of these surgical approaches continues and it is important to identify and summarise high-quality studies to make surgical treatment recommendations.

OBJECTIVES

To assess the effects of partial nephrectomy compared with radical nephrectomy for clinically localised renal cell carcinoma.

SEARCH METHODS

We searched CENTRAL, MEDLINE, PubMed, Embase, Web of Science, BIOSIS, LILACS, Scopus, two trial registries and abstracts from three major conferences to 24 February 2017, together with reference lists; and contacted selected experts in the field.

SELECTION CRITERIA

We included a randomised controlled trial comparing partial and radical nephrectomy for participants with small renal masses.

DATA COLLECTION AND ANALYSIS

One review author screened all of the titles and abstracts; only citations that were clearly irrelevant were excluded at this stage. Next, two review authors independently assessed full-text reports, identified relevant studies, evaluated the eligibility of the studies for inclusion, assessed trial quality and extracted data. The update of the literature search was performed by two independent review authors. We used Review Manager 5 for data synthesis and data analyses.

MAIN RESULTS

We identified one randomised controlled trial including 541 participants that compared partial nephrectomy to radical nephrectomy. The median follow-up was 9.3 years.Based on low quality evidence, we found that time-to-death of any cause was decreased using partial nephrectomy (HR 1.50, 95% CI 1.03 to 2.18). This corresponds to 79 more deaths (5 more to 173 more) per 1000. Also based on low quality evidence, we found no difference in serious adverse events (RR 2.04, 95% CI 0.19 to 22.34). Findings are consistent with 4 more surgery-related deaths (3 fewer to 78 more) per 1000.Based on low quality evidence, we found no difference in time-to-recurrence (HR 1.37, 95% CI 0.58 to 3.24). This corresponds to 12 more recurrences (14 fewer to 70 more) per 1000. Due to the nature of reporting, we were unable to analyse overall rates for immediate and long-term adverse events. We found no evidence on haemodialysis or quality of life.Reasons for downgrading related to study limitations (lack of blinding, cross-over), imprecision and indirectness (a substantial proportion of patients were ultimately found not to have a malignant tumour). Based on the finding of a single trial, we were unable to conduct any subgroup or sensitivity analyses.

AUTHORS' CONCLUSIONS

Partial nephrectomy may be associated with a decreased time-to-death of any cause. With regards to surgery-related mortality, cancer-specific survival and time-to-recurrence, partial nephrectomy appears to result in little to no difference.

Distinguishing pediatric and adolescent renal cell carcinoma from other renal malignancies

PURPOSE

Renal cell carcinoma (RCC) represents a small proportion of renal malignancies early in life. Distinguishing RCC from other malignancies is important as treatment strategies may differ. We analyze the Surveillance Epidemiology, and End Results (SEER) database to identify predictive factors of RCC in the pediatric population with renal tumors.

METHODS

We queried SEER to identify patients from ages 0 to 19 diagnosed with a renal malignancy between 1973 and 2013. Cases were sorted using histology and site codes. Age-adjusted standardized incidence rates (SIR) were calculated. We compared differences in characteristics between cancer types. A logistic regression model and a nomogram were created to identify predictors of RCC.

RESULTS

A total of 3,670 patients were identified, of which 281 (7.7%) were diagnosed with RCC. The SIR of RCC increased with age. After age 12, RCC was found in >50% of all newly diagnosed cases. On multivariate analysis, RCC was associated with smaller tumor size (P < 0.001), increasing age (P < 0.001), black race (P < 0.001), and localized stage (P < 0.001). The nomogram predicted RCC pathology with a concordance index of 0.965.

CONCLUSIONS

RCC in childhood and adolescence is relatively uncommon; however, it accounts for >50% of renal malignancies after age 12. For every year of increasing age, the odds of having an RCC diagnosis are increased by 50%. The odds of a renal tumor being RCC are increased in black children, those with localized disease, and those with smaller tumors. In these specific populations, RCC should be favored in the differential diagnosis of the renal mass.

Minimally invasive surgery in management of renal tumours in children

Minimally invasive surgery (MIS) in the management of malignant and benign renal tumours in children is gradually becoming more common. Experience is limited and restricted to case reports, retrospective chart reviews and a few cohort studies. There are currently no randomized controlled trials or controlled clinical trials comparing the laparoscopic and open surgical approach for the management of renal tumours in children. MIS may offer the same oncologic outcome in malignant renal tumours whilst providing the advantages associated with MIS in correctly selected cases. The technique for tumour resection has been shown to be feasible in regards to the recommended oncologic principles, although lymph node sampling can be inadequate in some cases. Preliminary reports do not show an increased risk of tumour rupture or inferior oncologic outcomes after MIS. However, the sample size remains small and duration of follow-up inadequate to draw any firm conclusions. Implementation of MIS is lacking in the protocols of the major study groups, and standardized recommendations for the indications and contra-indications remain undefined. The objective of this article is to present a review of the literature on the role of MIS in the management of renal tumours in children, with the main focus on Wilms' tumour (WT). Further studies on MIS in renal tumours are required to evaluate the incidence of oncological complications such as complete tumour resection and intra-operative tumour spillage. A long-term follow-up of patients managed by MIS is essential to compare recurrence rates and overall survival rates.

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.

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.

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.

The initial experience with RENAL Nephrometry in children, adolescents, and young adults with renal tumors

BACKGROUND

No standardized manner exits to objectively compare renal tumor complexity in children and adolescents. However, the RENAL Nephrometry scoring system has been recently developed in adults and shown to predict tumor complexity and correlate with clinical outcomes. Thus, the study objective was to evaluate RENAL Nephrometry tumor score in a population of children, adolescents, and young adults and correlate it with tumor features and pathology.

METHODS

Patients at the study institution who underwent attempted renal tumor resection from 2002 to 2012, and had pre-operative imaging available for scoring were retrospectively reviewed. A Nephrometry score for each affected kidney was calculated separately by two blinded reviewers and the final score was based on consensus review. Tumor characteristics and oncologic outcomes were compared between the low-, moderate-, and high-complexity masses.

RESULTS

Sixty-five patients and 67 kidneys met study criteria. This included: 5 (7.5%) low-complexity, 11 (16.4%) moderate-complexity, and 51 (76.1%) high-complexity lesions. In comparing the clinical and pathologic features between groups, it was observed that less complex masses were observed in older patients, were more commonly managed with nephron-sparing surgery, and more often represented renal cell carcinoma (RCC) and other non-Wilms tumor pathology. No statistically significant correlation was observed between tumor complexity score and blood loss, operative time, transfusion requirement, positive margins or tumor rupture.

CONCLUSION

In general, renal lesions in this population are highly complex. In its current form, RENAL Nephrometry appears most useful in evaluating tumor complexity in RCC and masses in older children and adolescents.

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.

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.

The evolution of treatment for Wilms tumor

The prognosis for children with Wilms tumor (WT) has improved dramatically as the result of advances in surgical techniques, anesthesia, and supportive care. During the last three decades, the National Wilms Tumor Study Group (NWTSG), the International Society of Pediatric Oncology (SIOP), and the United Kingdom Children's Cancer Study Group (UKCCSG) conducted sequential studies of treatments for children with WT. The National Wilms Study Group demonstrated that radiation therapy is not necessary for those with Stage I and II, favorable histology Wilms tumor, and that the dose necessary for local control for those with local Stage III disease is 1050 to 1080 cGy. Administration of actinomycin D and doxorubicin using a single dose rather than divided dose schedule produced less myelosuppression and equivalent outcomes. Loss of heterozygosity for chromosomes 1p and 16q was associated with an inferior outcome. Areas for future investigation include the role of whole lung irradiation in the treatment of those with pulmonary metastases, the use of parenchymal sparing surgical techniques for removal of Wilms tumors, and identification of minimal necessary therapy.

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.

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.