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

WT1-related disorders: more than Denys-Drash syndrome

Historically, specific mutations in WT1 gene have been associated with distinct syndromes based on phenotypic characteristics, including Denys-Drash syndrome (DDS), Frasier syndrome (FS), Meacham syndrome, and WAGR syndrome. DDS is classically defined by the triad of steroid-resistant nephrotic syndrome (SRNS) onset in the first year of life, disorders of sex development (DSD), and a predisposition to Wilms tumor (WT). Currently, a paradigm shift acknowledges a diverse spectrum of presentations beyond traditional syndromic definitions. Consequently, the concept of WT1-related disorders becomes more precise. A genotype-phenotype correlation has been established, emphasizing that the location and type of WT1 mutations significantly influence the clinical presentation, the condition severity, and the chronology of patient manifestations. Individuals presenting with persistent proteinuria, with or without nephrotic syndrome, and varying degrees of kidney dysfunction accompanied by genital malformations should prompt suspicion of WT1 mutations. Recent genetic advances enable a more accurate estimation of malignancy risk in these patients, facilitating a conservative nephron-sparing surgery (NSS) approach in select cases, with a focus on preserving residual kidney function and delaying nephrectomies. Other key management strategies include kidney transplantation and addressing DSD and gonadoblastoma. In summary, recent genetic insights underscore the imperative to implement individualized, integrated, and multidisciplinary management strategies for WT1-related disorders. This approach is pivotal in optimizing patient outcomes and addressing the complexities associated with these diverse clinical manifestations.

Major surgical conditions of childhood and their lifelong implications: comprehensive review

BACKGROUND

In recent decades, the survival of children with congenital anomalies and paediatric cancer has improved dramatically such that there has been a steady shift towards understanding their lifelong health outcomes. Paediatric surgeons will actively manage such conditions in childhood and adolescence, however, adult surgeons must later care for these 'grown-ups' in adulthood. This article aims to highlight some of those rare disorders encountered by paediatric surgeons requiring long-term follow-up, their management in childhood and their survivorship impact, in order that the adult specialist may be better equipped with skills and knowledge to manage these patients into adulthood.

METHODS

A comprehensive literature review was performed to identify relevant publications. Research studies, review articles and guidelines were sought, focusing on the paediatric management and long-term outcomes of surgical conditions of childhood. The article has been written for adult surgeon readership.

RESULTS

This article describes the aforementioned conditions, their management in childhood and their lifelong implications, including: oesophageal atresia, tracheo-oesophageal fistula, malrotation, short bowel syndrome, duodenal atresia, gastroschisis, exomphalos, choledochal malformations, biliary atresia, Hirschsprung disease, anorectal malformations, congenital diaphragmatic hernia, congenital lung lesions and paediatric cancer.

CONCLUSION

The increasing survivorship of children affected by surgical conditions will translate into a growing population of adults with lifelong conditions and specialist healthcare needs. The importance of transition from childhood to adulthood is becoming realized. It is hoped that this timely review will enthuse the readership to offer care for such vulnerable patients, and to collaborate with paediatric surgeons in providing successful and seamless transitional care.

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.

Utilizing RENAL nephrometry in pediatric patients undergoing nephron-sparing surgery for renal tumors: A single-institutional cohort

INTRODUCTION

RENAL Nephrometry is a complexity score validated in adults with renal tumors and describes the likelihood of complication after partial nephrectomy (PN). Utilization in pediatrics has been limited. Thus, our goal is to quantify inter-rater agreement as well as determine how scores correlate with outcomes. We hypothesize that the RENAL Nephrometry Score is reproducible in children with renal tumors and is related to perioperative and post-operative complications.

METHODS

All pediatric patients who underwent PN for a renal mass from 2006 to 2019 were identified. Patient data, operative details, and outcomes were aggregated. Pre-operative CT/MR imaging was anonymized and scored by 2 pediatric radiologists and 2 pediatric urologists using RENAL Nephrometry metrics. Statistical analysis utilized Fleiss' kappa and the intraclass correlation coefficient (ICC). Comparative analyses were performed based on Nephrometry Score <9 and ≥ 9.

RESULTS

28 patients undergoing 33 PN were identified. Median age at surgery was 3.2 years (IQR 1.8-4.0). There is moderate-good agreement across scorers on the domains of RENAL Nephrometry Score, with the lowest agreement noted for anterior vs posterior tumors. Comparing patients with scores <9 and ≥ 9, there was increased operative time (357 vs 267 min, p = 0.003) and LOS for those with a higher score, but no difference in the incidence of 30-day complications.

CONCLUSION

RENAL Nephrometry Score is an easily reproducible complexity score for renal tumors in pediatric patients. Higher scores are associated with increased length of stay and estimated blood loss but not complications. Reporting of nephrometry scores in future publications on pediatric renal tumors should become standard in the literature.

Nephron-sparing surgery for Wilms tumor

The algorithm that has been used successfully in the surgical management of unilateral Wilms tumor, radical nephroureterectomy, cannot be used in children who present with synchronous bilateral renal masses. Instead, a surgical approach that removes all tumor masses while preserving as much normal renal parenchyma as possible is encouraged to avoid acute and long-term renal insufficiency. We will review technical aspects of the conduct of nephron-sparing surgery for synchronous bilateral Wilms tumor, including the more recent advances in the use of imaging adjuncts such as pre-operative 3D imaging and fluorescence-guided surgery. The potential role of nephron-sparing surgery for unilateral Wilms tumor will also be discussed.

The varied spectrum of nephroblastomatosis, nephrogenic rests, and Wilms tumors: Review of current definitions and challenges of the field

The diagnosis of multiple or diffuse renal lesions in a child is challenging by imaging and/or pathology. Optimal management requires distinguishing benign lesions such as nephrogenic rests from cancerous lesions such as Wilms tumor, but this is often difficult or impossible. This difficulty is compounded by the overlapping nature of our current radiologic and pathologic definitions of lesions along the spectrum of nephrogenic rests/nephroblastomatosis. We provide a review of these issues, as a collaborative effort between the Children's Oncology Group Renal Tumor Committee and International Society of Pediatric Oncology Renal Tumor Study Group. Our aim is to discuss current challenges in diagnosis and management of these renal lesions, encouraging future work toward consensus definitions for research and patient care.

Increased risk for kidney sequelae surrogates in survivors of Wilms tumor

BACKGROUND

There is evidence of increased risk of hypertension, albuminuria, and development of chronic kidney disease (CKD) in long-term follow-up of survivors of Wilms tumor (WT). However, most studies were conducted in heterogeneous groups, including patients with solitary kidney. In addition, little is known about tubular dysfunction. This study aimed to investigate kidney sequelae, including CKD development, hypertension, and glomerular and tubular damage in WT survivors.

METHODS

This cross-sectional, single-center study included 61 patients treated for WT. Surrogates for kidney sequelae were defined as presence of at least one of the following: decrease in GFR for CKD, hypertension detected by ambulatory blood pressure monitoring, albuminuria (albumin-to-creatinine ratio [ACR] > 30 mg/g), or increase in at least one tubular biomarker (beta-2-microglobulin, neutrophil gelatinase-associated lipocalin, kidney injury marker-1, and liver fatty acid-binding protein) in 24-h urine.

RESULTS

Median age of patients was 11.7 years, with median follow-up of 8.8 years. Thirty-eight patients (62%) had at least one surrogate for kidney sequelae. Twenty-four patients (39%) had CKD, 14 patients (23%) had albuminuria, 12 patients (21%) had hypertension, and 11 patients (18%) had tubular damage. Urine ACR was significantly higher in patients with advanced tumor stage and patients with nephrotoxic therapy than their counterparts (p < 0.05), but neither eGFR nor tubular biomarkers showed any association with tumor- or treatment-related factors.

CONCLUSIONS

A considerable number of patients with WT have kidney sequelae, especially early-stage CKD with a high prevalence. Albuminuria emerges as a marker associated with tumor stages and nephrotoxic treatment. A higher resolution version of the Graphical abstract is available as Supplementary information.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Cystic Nephroma and its Varied Management Scenarios: A Report of two Cases

Cystic nephroma is a rare benign cystic neoplasm of the kidney. The preoperative diagnosis with its malignant counterparts cystic partially differentiated nephroblastoma or cystic Wilms' tumor is not easy but is important when one is considering for nephron-sparing surgery.

Abdominal Recurrence after Robotic Nephron-Sparing Surgery for Wilms Tumor in an Adult Patient

A 31-year-old man was referred to an adult urologist for a renal polar mass that measured 7.2 cm in maximum diameter. Robotic assisted complete tumor excision for suspicious renal cell carcinoma was carried out, preserving the rest of the left kidney. Histopathology showed a Wilms tumor (WT) with positive margins. No postoperative therapy was made, and the patient shortly presented an abdominal recurrence. The patient was referred to our pediatric oncology unit; he received preoperative chemotherapy, followed by surgery (completion nephrectomy and removal of neoplastic deposits in the omentum and parietal peritoneum), postoperative chemotherapy, and abdomen radiotherapy. He is well at the 5-year follow-up. Peritoneal dissemination after laparoscopic nephron-sparing surgery (NSS) in a child with a 10-cm WT was previously reported. We suggest open NSS for large WT may be safer than laparoscopic or robotic NSS because carbon dioxide pneumoperitoneum and traumatic handling of tumor may predispose to tumor cell migration. An abdominal WT relapse in adults can be salvaged by multimodal therapy recommended by current pediatric WT guidelines.

A Role of brachytherapy in bilateral Wilms tumors: A long-term follow-up of three highly selected cases and literature review

PURPOSE

To describe experience with partial nephrectomy combined with brachytherapy as part of the local management of bilateral Wilms tumor (WT) including a review of the available literature.

RESULTS (METHODS AND CASE DESCRIPTION)

Between 2011 and 2014, three highly selected patients (age nine months, 16 months, and 4 years) with bilateral WT (two synchronous and one metachronous) underwent enucleation and perioperative brachytherapy to the tumor bed. With a minimum follow-up of 5 years, all three patients are in continuous complete remission with preserved kidney function.

CONCLUSIONS

Although nephron sparing surgery aiming at tumor free-margins remains the gold standard for bilateral WT, tumor enucleation followed by brachytherapy may be considered in carefully selected patients at high risk for end-stage kidney failure. Given the rarity and complexity of the procedure, concentration of care of such patients is mandatory.

Evaluation of the nephron-sparing surgery formula in Wilms tumors

AIM

Definitions of nephron-sparing surgery (NSS) procedures in Wilms tumor (WT) are not clear. The new UMBRELLA protocol offers a formula (NSS(X)-SRM(n)-PRM(n)-RRP(n%)) to better define the different NSS parameters. We aimed to assess the advantages and limits of this new formula.

METHODS

This retrospective monocentric study included patients operated by NSS for WT from 1975 to 2018. We reviewed the medical records and applied the NSS formula to all included patients.

RESULTS

Eighty kidneys were operated on 56 patients at a mean age of 19.2 months (4 days-7.5 years), with 49 partial nephrectomies and 31 tumorectomies. The assessment of the surgical resection margins (SRM) showed a doubt in six cases and one tumor breach. An intact pseudocapsule along the resection margin with no renal parenchyma was found in four cases at pathological resection margins (PRM) assessment, whereas a tumor breach was described in seven cases. Among the six patients with a surgical doubt, only one had a pathological stage III. There were no surgical doubts in the seven patients with tumor breach at pathology. At a mean follow-up of eight years (15 days-28.6 years), eight patients had elevated blood pressure levels. Ten had proteinuria. These two parameters were significantly increased in patients with a remaining renal parenchyma (RRP) of less than half of the initial total renal parenchyma. The serum creatinine level was normal for all except two patients.

CONCLUSION

The new NSS formula described all the crucial elements of NSS. RRP seemed essential for the evaluation of long-term renal function.

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.

Nephron Sparing Surgery for Synchronous Bilateral Wilms-Operative Steps

Approximately 5% of children with Wilms tumor present with bilateral disease. The treatment challenge is to achieve a high cure rate while maintaining adequate long-term renal function. We report the feasibility and outcome of nephron sparing surgery in a child with bilateral Wilms tumor who was treated at our institution.

Bilateral Wilms Tumor: A Surgical Perspective

Historically, the management of bilateral Wilms tumor (BWT) was non-standardized and suffered from instances of prolonged chemotherapy and inconsistent surgical management which resulted in suboptimal renal and oncologic outcomes. Because of the risk of end-stage renal disease associated with the management of BWT, neoadjuvant chemotherapy and nephron-sparing surgery have been adopted as the guiding management principles. This management strategy balances acceptable oncologic outcomes against the risk of end-stage renal disease. A recent multi-institutional Children’s Oncology Group study (AREN0534) has confirmed the benefits of standardized 3-drug neoadjuvant chemotherapy and the utilization of nephron-sparing surgery in BWT patients; however, less than 50% of patients underwent bilateral nephron-sparing surgery. The coordination of neoadjuvant chemotherapy and the timing and implementation of bilateral nephron-sparing surgery are features of BWT management that require collaboration between oncologists and surgeons. This review discusses the surgical management strategy in the context of BWT disease biology, with an emphasis on timepoints during therapy at which surgical decision making can greatly impact this disease and minimize long-term toxicities.

Evidence-based paediatric surgical oncology

Surgeons play a pivotal role in the decision-making and multidisciplinary management of childhood solid tumours.¹ Evidence-based medicine-"aims to optimise decision making by emphasising on the use of best evidence from well-designed conducted research." This article offers a brief overview in an effort to demonstrate how a selection of well-conducted, recently published studies can help address some topical and controversial themes in paediatric surgical oncology practice.

Overall Survival and Renal Function of Patients With Synchronous Bilateral Wilms Tumor Undergoing Surgery at a Single Institution

OBJECTIVES

Wilms tumor is the most common renal cancer in children. Approximately 5% of children with Wilms tumor present with disease in both kidneys. The treatment challenge is to achieve a high cure rate while maintaining long-term renal function. We retrospectively reviewed our institutional experience with nephron sparing surgery (NSS) in patients with synchronous bilateral Wilms tumor (BWT) operated on between 2001 and 2014.

METHODS

Imaging studies, surgical approach, adjuvant therapy, and pathology reports were reviewed. Outcomes evaluated included surgical complications, tumor recurrence, patient survival, and renal function, as assessed by estimated glomerular filtration rate.

RESULTS

A total of 42 patients with BWT were identified: 39 (92.9%) patients underwent bilateral NSS; only 3 patients (7.1%) underwent unilateral nephrectomy with contralateral NSS. Postoperative complications included prolonged urine leak (10), infection (6), intussusception (2), and transient renal insufficiency (1). Three patients required early (within 4 months) repeat of NSS for residual tumor. In the long-term, 7 (16.7%) patients had local tumor recurrence (managed with repeat NSS in 6 and completion nephrectomy in 1) and 3 had an episode of intestinal obstruction requiring surgical intervention. Overall survival was 85.7% (mean follow-up, 4.1 years). Of the 6 patients who died, 5 had diffuse anaplastic histology. All of the patients had an estimated glomerular filtration rate more than 60 mL/min/1.73 m at the last follow-up; no patient developed end-stage renal disease.

CONCLUSIONS

In patients with synchronous, BWT, bilateral NSS is safe and almost always feasible, thereby preserving maximal renal parenchyma. With this approach, survival was excellent, as was maintenance of the renal function.

Current surgical standards of care in Wilms tumor

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Minimally invasive nephrectomy for Wilms tumors in children - data from SIOP 2001

PURPOSE

To analyse the surgical and oncological outcome of minimally invasive surgery (MIS) for tumor nephrectomy in Wilms tumor (WT) patients.

METHODS

WT patients from the SIOP 2001 trial, undergoing MIS for tumor nephrectomy were analyzed with regard to demographic characterization, surgical specifications, complications, and outcome.

RESULTS

There were 24 children matching the inclusion criteria. Median age at operation was 40.35 months (14.3-65.4). All patients received preoperative chemotherapy. Median tumor volume was 177.5 ml at diagnosis (46.5-958) and 73.0 ml at surgery (3.8-776). There was one surgical complication (splenic injury), no intraoperative tumor rupture occurred. Abdominal stage was I in 14, II in 7, and III in 3 patients. Adequate lymph node sampling was performed in only 2 patients. One local relapse occurred. Event-free survival was 23/24, overall survival was 24/24, median follow up was 47 months (2-114).

CONCLUSIONS

We present the largest series so far of minimally invasive nephrectomies for nephroblastoma based on a multinational trial. Treatment results were comparable to those of open surgery; however, experience of operating surgeons was generally high. Discipline of lymph node sampling was inadequate. Based on this analysis a prospective study on MIS in nephroblastoma is planned by the SIOP Renal Tumor Study Group.

Impact of nephrectomy on long-term renal function in non-syndromic children treated for unifocal Wilms tumor

OBJECTIVE

The present study is designed to assess the long-term renal function of children who underwent radical nephrectomy for unifocal Wilms tumor.

METHODS

A single institution retrospective cohort study of non-syndromic children treated with radical nephrectomy for unifocal Wilms tumor between 1995 and 2011 was performed to identify risk factors for decreased glomerular filtration rate (GFR). The primary endpoint was decrease in age-adjusted GFR below normal published ranges. The secondary endpoint was progression to chronic renal insufficiency (CRI).

RESULTS

A total of 55 patients were identified in the cohort. Eight (15%) patients exhibited decreased age-adjusted GFR during the follow-up period, with 2 (4%) progressing to CRI. Increasing time between surgery and the last known GFR follow-up was associated with decreased GFR, with the normal GFR group having median follow-up of 7.32 years versus 11.47 years (p = 0.019) in the decreased GFR group.

CONCLUSIONS

A trend toward decline in GFR was detected with longer follow-up. Longer follow-up may reveal that clinically significant decline in renal function occurs years following nephrectomy among a subset of Wilms tumor survivors, even among those who do not progress to end stage renal disease.

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.

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 use of Tachosil as hemostatic sealant in nephron sparing surgery for Wilms tumor: preliminary observations

BACKGROUND

TachoSil, which is an absorbable collagen sponge coated with human fibrinogen and thrombin, has proven to enhance hemostasis and promote optimal wound healing in adults undergoing nephron sparing surgery (NSS). We report our preliminary experience using this hemostatic agent during NSS in children.

METHODS

Prospective analysis of 3 patients with Wilms tumor (synchronous bilateral in one) undergoing NSS at our institution over an 18-month period. Primary outcome measures were intraoperative bleeding control and surgery-related postoperative sequelae.

RESULTS

Overall, 4 kidneys underwent 5 NSS procedures, which included 3 partial nephrectomies and multiple tumor excisions performed on another kidney at initial and second-look surgery. After control of major bleeding and suturing of the collecting system, which was entered during 2 of the 5 NSS procedures, TachoSil was applied to the parenchymal surface of the kidney, achieving immediate hemostasis. All NSS procedures were performed without hilar clamping, drainage or stent placement. None of the patients required blood transfusion. Small perirenal fluid collections were documented postoperatively, and all spontaneously resolved within 4 weeks of surgery.

CONCLUSION

In children undergoing NSS, TachoSil represents an effective and safe tool for control of mild to moderate bleeding, and also facilitates sealing and wound dressing.

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.

Minimally invasive nephron-sparing surgery for unilateral Wilms tumor

Minimally invasive surgery (MIS) for nephrectomy has been described since the early 1990s. More recently, MIS has been used for nephron-sparing surgery (NSS) when treating benign conditions. However, reports of NSS using MIS for malignant conditions are sparse. In this report, we describe our retroperitoneal laparoscopic approach for NSS for a localized Wilms tumor.

Nephron-sparing partial nephrectomy for bilateral Wilms' tumor

PURPOSE

Partial nephrectomy is increasingly used in children with bilateral Wilms' tumor (BWT) or contralateral recurrence. Nephron-sparing surgery seeks to achieve complete tumor removal while preserving functional renal parenchyma. Previous series have documented high rates of complications, recurrence, and mortality.

METHODS

Twelve patients (4 boys and 8 girls aged 9-42 months) with BWT or contralateral recurrence were treated at our institution with unilateral or bilateral partial nephrectomy. Preoperative imaging, operative notes, and pathology reports were reviewed. Outcomes analyzed included complications, recurrence, readmission rate, postoperative glomerular filtration rate (GFR), and survival.

RESULTS

All patients underwent successful nephron-sparing resection using standard techniques, with only 2 patients requiring unilateral nephrectomy. Median length of stay was 3 days. There were no major complications or urine leaks. Two patients were lost to follow-up. The remaining 10 were followed up for a median of 36 months (range, 3-79 months). There have been no recurrences or unplanned readmissions. Mean GFR is 107.7 (± 32.8) mL/min per 1.73 m(2), with no patient having a GFR below the lower limit of normal for age.

CONCLUSION

Nephron-sparing resection is a safe and effective approach for children with BWT or contralateral recurrence and should be part of the multimodality therapeutic approach to this disease.

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.

Nephroblastoma: does the decrease in tumor volume under preoperative chemotherapy predict the lymph nodes status at surgery?

BACKGROUND

Partial nephrectomy (NSS) for unilateral nephroblastoma may be beneficial, although in case of regional lymph node (LN) involvement, radiotherapy counteracts the functional benefit of NSS. The aim is to verify whether decrease of tumor volume under preoperative chemotherapy implies clearance of regional LN.

PROCEDURE

SIOP 9301 (1993-2001) collected 1,450 localized nephroblastoma patients of whom 1,360 (93%) had sufficiently available data and were retrospectively reviewed.

RESULTS

Histologic subtypes were classically distributed. Patients were divided in those with tumor positive LN (76, 5.5%) and those with tumor negative LN (1,284, 94.5%) at surgery. In the LN(+) group, the tumor volume changed from a median of 554 (318-772) to 192 (63-458) ml = 67% (27-88%) during preoperative ChT. In the LN(-) group-377 (200-612) to 130 (44-294) ml = 62% (28-83%) (NS). Increase of tumor volume was observed in 16% of patients with LN(+), and 11% of those with LN(-) (NS); ranges are interquartile. Initial tumor volume was significantly larger in the LN(+) patients (P = 0.00091) but not different (NS) at surgery; patients with initial tumor volume under 318 ml had the regional LN involved significantly less frequently (P = 0.00751).

CONCLUSIONS

Change in tumor volume under preoperative chemotherapy is not a predictor for LN status at surgery, although larger initial volume is associated with a higher risk of LN invasion. The decrease of tumor volume is not a good criterion for the safety of NSS. The low rate of LN(+) (5.5%) indicates that this risk is low.

Peritoneal metastases after laparoscopic nephron-sparing surgery for localized Wilms tumor

A 2-year-old girl was referred for the management of the progression of her localized Wilms tumor. She had undergone laparoscopic nephron-sparing surgery for her right Wilms tumor 3 months earlier. Postoperative chemotherapy was commenced 6 weeks later. Subsequent computer tomographic evaluation 12 weeks postsurgery showed local recurrence and peritoneal tumors. These findings were confirmed at laparotomy. We report the first case of peritoneal tumor dissemination after laparoscopic nephron-sparing surgery for localized Wilms tumor.

Renal glomus tumor in an adolescent: a conservative approach

The most common renal neoplasms in the second decade of life are renal cell carcinomas and Wilms' tumors. Glomus tumors arising in the kidney are rare. We report an adolescent with a benign renal glomus tumor excised by wedge resection. Nephron-sparing surgery is the therapy of choice for children with benign renal tumors. Glomus tumor should be considered in the differential diagnosis of a renal mass in a young patient.

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.