Long-term outcome of bilateral Wilms tumors (BWT)

Characteristics and outcome of synchronous bilateral Wilms tumour in the SIOP WT 2001 Study: Report from the SIOP Renal Tumour Study Group (SIOP-RTSG)

BACKGROUND

Among patients with nephroblastoma, those with bilateral disease are a unique population where maximising tumour control must be balanced with preserving renal parenchyma.

METHODS

The SIOP 2001 protocol recommended surgery after neoadjuvant cycle(s) of Dactinomycin and Vincristine (AV) with response-adapted intensification, if needed. Adjuvant treatment was given based on the lesion with the worst histology.

RESULTS

Three hundred and twenty seven patients with stage V disease were evaluable: 174 had bilateral Wilms tumour (BWT), 101 unilateral WT and contralateral nephroblastomatosis (NB) and 52 bilateral nephroblastomatosis. In these three groups, the estimated 5y-EFS was 76.1%, 84.6%, and 74.9%, respectively. AV chemotherapy alone was the successful chemotherapy for 58.7% of all the patients and 65.6% of the non-metastatic patients. Among the 174 patients with BWT, 149 (88.2%) had at least one nephron-sparing surgery. Twenty of 61 bilateral stage I patients were treated with four-week AV postoperatively achieving 94.4% 5y-EFS. At last follow-up, 87% of patients had normal renal function.

CONCLUSIONS

This study demonstrates that AV without anthracyclines is sufficient to achieve NSS and good survival in the majority of patients. For patients with bilateral stage I WT and intermediate risk histology, only four weeks adjuvant AV seems to be sufficient.

CLINICAL TRIAL REGISTRATION

NCT00047138.

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.

Long-term nephrotoxicity in irradiated pediatric kidney tumor survivors: A systematic review

OBJECTIVE

Nephrotoxicity can occur as a side effect after treatment for kidney tumor in childhood. The use of radiotherapy (RT) has a potential additional effect.

METHODS

A systematic electronic literature search that combined childhood kidney cancer with different treatments and nephrotoxicity terms was performed in EMBASE. Studies were included based on the reporting of nephrotoxicity occurrence after treatment for kidney tumor during pediatric age, with 75% of participants being under the age of 25 years at the time of diagnosis, and having been treated with any type of kidney surgery, chemotherapy, and/or RT.

RESULTS

A pooled analysis did not show significant difference in estimated glomerular filtration rate between the group of patients who received RT compared with the group treated without RT (SMD -0.11 [95% CI -1.07-0.84] p = .733).

CONCLUSION

The current literature suggests that the use of RT does not have a significant impact on the decline of kidney function as independent factor.

Meta-Analysis on Long-Term Outcomes of Pediatric Renal Cancer Survivors Following COG and SIOP Protocols

BACKGROUND

 Pediatric renal cancer survivors have higher rate of chronic renal disease and hypertension. These patients have similar survival rates when treated according to either Children's Oncology Group (COG) or International Society of Pediatric Oncology (SIOP) protocols. We aimed to compare the late outcome of these two approaches.

METHODS

 We performed a meta-analysis of all studies from 2000 to 2021; database search using keywords: long-term outcomes OR late effects, nephrectomy, pediatric renal cancer. For each protocol, data were collected, and the "pooled" outcomes were compared. Continuous and dichotomous variables were obtained with a 95% odds ratio.

RESULTS

 Sixteen studies with a total of 715 pediatric renal cancer survivors were analyzed. The mean follow-up time was 17.4 (standard deviation 5.6) years. Reduced renal function and hypertension were the most encountered long-term complications. The mean estimated glomerular filtration rate was similar in both protocols (101.62 vs. 101.70 mL/min/1.73 m²), while the prevalence of hypertension was 23% in COG and 10% in SIOP. The prevalence of secondary malignancy was 1.1% in COG and 6.7% in SIOP (1.1% vs. 6.7%, p ≤ 0.001). Chronic kidney disease was similar in both groups.

CONCLUSION

 A high prevalence of hypertension was observed among pediatric renal cancer survivors, as well as an increased risk of a secondary tumor. These results emphasize the importance of long-term follow-up into adulthood, to promptly diagnose any long-term side effects of the treatment. Thanks to the increased overall survival, future protocols will pay attention to the reduction of long-term sequelae.

Outcomes according to treatment using an established protocol in patients with bilateral Wilms' tumor: A national Canadian population-based study

BACKGROUND

Bilateral Wilms tumor (BWT) is a rare entity. The goal of this study is to report outcomes (overall and event-free survival, OS/EFS) of BWT in a large cohort representative of the Canadian population since 2000. We focused on the occurrence of late events (relapse or death beyond 18 months), as well as outcomes of patients treated following the only protocol specifically designed for BWT to date, AREN0534, compared to patients treated following other therapeutic schemes.

METHODS

Data was obtained for patients diagnosed with BWT between 2001 and 2018 from the Cancer in Young People in Canada (CYP-C) database. Demographics, treatment protocols, and dates for events were collected. Specifically, we examined outcomes of patients treated according to the Children's Oncology Group (COG) protocol AREN0534 since 2009. Survival analysis was performed.

RESULTS

57/816 (7%) of patients with Wilms tumor had BWT during the study period. Median age at diagnosis was 2.74 years (IQR 1.37-4.48) and 35 (64%) were female; 8/57 (15%) had metastatic disease. After a median follow-up of 4.8 years (IQR 2.8-5.7 years, range 0.2-18 years), OS and EFS were 86% (CI 73-93%) and 80% (CI 66-89%), respectively. Less than 5 events were recorded after 18 months from diagnosis. Since 2009, patients treated according to the AREN0534 protocol had a statistically significant higher OS compared to patients treated with other protocols.

CONCLUSIONS

In this large Canadian cohort of patients with BWT, OS and EFS compared favorably to the published literature. Late events were rare. Patients treated according to a disease-specific protocol (AREN0534) had improved overall survival.

TYPE OF STUDY

Original article.

LEVEL OF EVIDENCE

Level IV.

Bilateral Renal Tumors in Children: The First 5 Years' Experience of National Centralization in The Netherlands and a Narrative Review of the Literature

Survival of unilateral Wilms tumors (WTs) is exceeding 90%, whereas bilateral WTs have an inferior outcome. We evaluated all Dutch patients with bilateral kidney tumors, treated in the first five years of national centralization and reviewed relevant literature. We identified 24 patients in our center (2015–2020), 23 patients had WT/nephroblastomatosis and one renal cell carcinoma. Patients were treated according to SIOP-RTSG protocols. Chemotherapy response was observed in 26/34 WTs. Nephroblastomatosis lesions were stable (n = 7) or showed response (n = 18). Nephron-sparing surgery was performed in 11/22 patients undergoing surgery (n = 2 kidneys positive margins). Local stage in 20 patients with ≥1 WT revealed stage I (n = 7), II (n = 4) and III (n = 9). Histology was intermediate risk in 15 patients and high risk in 5. Three patients developed a WT in a treated nephroblastomatosis lesion. Two of 24 patients died following toxicity and renal failure, i.e., respectively dialysis-related invasive fungal infection and septic shock. Genetic predisposition was confirmed in 18/24 patients. Our literature review revealed that knowledge is scarce on bilateral renal tumor patients with metastases and that radiotherapy seems important for local stage III patients. Bilateral renal tumors are a therapeutic challenge. We describe management and outcome in a national expert center and summarized available literature, serving as baseline for further improvement of care.

Bilateral Wilms' tumour: An international comparison of treatments and outcomes

INTRODUCTION

Wilms' tumour is the most common childhood renal malignancy, with 5-10% of cases presenting bilaterally ¹. However, there is currently no consensus between centres on optimal management of bilateral Wilms' tumours. This is an international multi-centre case series comparing management and outcomes of bilateral Wilms' tumours between low-income centres (LIC) and high-income centres (HIC).

METHODS

Patients with bilateral Wilms' tumour were identified from four tertiary referral centres internationally. Data were collected on baseline characteristics, disease status, treatment used and clinical outcomes. Results were compared between individual centres as well as between groups of low-income centres (LIC) and high-income centres (HIC).

RESULTS

Data were collected for forty patients. Most patients received preoperative chemotherapy (n = 38, 95%). The most common surgical procedures were bilateral nephron-sparing surgery (n = 10, 25%) and nephrectomy with partial nephrectomy (n = 20, 50%). Ten-year survival after treatment was as follows: LIC's n = 13 (65%); HIC's n = 20 (100%) (p = 0.01).

DISCUSSION

Ten-year survival was significantly higher in HIC's. Our results show this may be caused by patient factors such as later presentation with more advanced disease in low-income centres. This comparative case series is the first to report on a large number of cases from multiple international centres, and to compare key outcomes.

Wilms Tumor Associated With the 9q22.3 Microdeletion Syndrome: 2 New Case Reports and a Review of The Literature

BACKGROUND

The 9q22.3 syndrome is an autosomal dominant microdeletion syndrome with similarities to Gorlin syndrome (GS). It encompasses the PTCH1 gene locus that harbors mutations for GS. Although the 9q22.3 syndrome is associated with Wilms tumor (WT), WT is not a GS-associated tumor, implying a different mechanism involving PTCH1, or a different locus in the 9q22.3 region. The goal of this study is to report the association between WT and 9q22.3 syndrome and review the outcome of treatment.

OBSERVATIONS

We report 2 new cases of WT with 9q22.3 deletion and review the literature. Among the 44 described patients with 9q22.3 deletion, 7 developed WT (16%) at a mean age of 45 months (range, 4 to 84 mo). All patients had dysmorphic features, macrocephaly, and developmental delay, and there was an association with overgrowth (4/7). One patient had bilateral WT, another had a synchronous rhabdomyosarcoma. The outcome was excellent with all cases reported to be in complete remission.

CONCLUSIONS

The 9q22.3 microdeletion syndrome should be considered at diagnosis of WT in children with dysmorphic features. Conversely, patients with a known 9q22.3 deletion syndrome should be considered for a WT predisposition surveillance program, especially those with overgrowth. The management should be individualized and given the excellent prognosis, and the unknown future risk of metachronous disease or other malignancy, the surgical approach should be carefully considered.

Solid organ transplantation after treatment for childhood cancer: a retrospective cohort analysis from the Childhood Cancer Survivor Study

BACKGROUND

Serious chronic medical conditions occur in childhood cancer survivors. We aimed to investigate incidence of and risk factors for end-organ damage resulting in registration on a waiting list for or receiving a solid organ transplantation and 5-year survival following these procedures.

METHODS

The Childhood Cancer Survivor Study (CCSS) is a retrospective cohort of individuals who survived at least 5 years after childhood cancer diagnosed at younger than 21 years of age, between Jan 1, 1970, and Dec 31, 1986, at one of 25 institutions in the USA. We linked data from CCSS participants treated in the USA diagnosed between Jan 1, 1970, and Dec 31, 1986 (without solid organ transplantation before cohort entry) to the Organ Procurement and Transplantation Network-a database of all US organ transplants. Eligible participants had been diagnosed with leukaemia, lymphoma, malignant CNS tumours, neuroblastoma, Wilms' tumours, and bone and soft tissue sarcomas. The two primary endpoints for each type of organ transplant were date of first registration of a transplant candidate on the waiting list for an organ and the date of the first transplant received. We also calculated the cumulative incidence of being placed on a waiting list or receiving a solid organ transplantation, hazard ratios (HRs) for identified risk factors, and 5-year survival following transplantation.

FINDINGS

Of 13 318 eligible survivors, 100 had 103 solid organ transplantations (50 kidney, 37 heart, nine liver, seven lung) and 67 were registered on a waiting list without receiving a transplant (21 kidney, 25 heart, 15 liver, six lung). At 35 years after cancer diagnosis, the cumulative incidence of transplantation or being on a waiting list was 0·54% (95% CI 0·40-0·67) for kidney transplantation, 0·49% (0·36-0·62) for heart, 0·19% (0·10-0·27) for liver, and 0·10% (0·04-0·16) for lung. Risk factors for kidney transplantation were unilateral nephrectomy (HR 4·2, 95% CI 2·3-7·7), ifosfamide (24·9, 7·4-83·5), total body irradiation (6·9, 2·3-21·1), and mean kidney radiation of greater than 15 Gy (>15-20 Gy, 3·6 [1·5-8·5]; >20 Gy 4·6 [1·1-19·6]); for heart transplantation, anthracycline and mean heart radiation of greater than 20 Gy (dose-dependent, both p<0·0001); for liver transplantation, dactinomycin (3·8, 1·3-11·3) and methotrexate (3·3, 1·0-10·2); for lung transplantation, carmustine (12·3, 3·1-48·9) and mean lung radiation of greater than 10 Gy (15·6, 2·6-92·7). 5-year overall survival after solid organ transplantation was 93·5% (95% CI 81·0-97·9) for kidney transplantation, 80·6% (63·6-90·3) for heart, 27·8% (4·4-59·1) for liver, and 34·3% (4·8-68·6) for lung.

INTERPRETATION

Solid organ transplantation is uncommon in ageing childhood cancer survivors. Organ-specific exposures were associated with increased solid organ transplantation incidence. Survival outcomes showed that solid organ transplantation should be considered for 5-year childhood cancer survivors with severe end-organ failure.

FUNDING

US National Institute of Health, American Lebanese Syrian Associated Charities, US Health Resources and Services Administration.

National Survey on the Management of Wilms Tumor

This study aims to investigate the management of Wilms tumor by the Egyptian pediatric surgical association (EPSA) consultants. After approval of the EPSA executive board, a questionnaire was distributed individually to all consultants attending the general assembly of EPSA 2017 annual congress. Of 88 consultants, responses were received from 61. Palpable abdominal mass was indicated by 72.13% of respondents as the commonest presenting symptom. Concerning the imaging requested, computed tomography was reported by 80.33%. Approximately 62.30% of respondents perform 1 to 3 cases annually. Regarding timing of surgery, upfront resection was the most frequently reported by 62.30%. A total of 77.05% perform lymph node sampling during surgeries. Nephron-sparing surgery was adopted by only 26.23%, whereas none of the respondents reported the use of minimally invasive surgery for management. Overall, 93.44% of surgeons ask for a visit every 3 months in the first year postoperatively. Upfront nephrectomy is the commonest procedure for Wilms tumor in the current practice of EPSA consultants, whereas there is consensus against minimally invasive surgery. Surgical guidelines for nephron-sparing surgery are still incomplete and need to be tabulated. This study urges for a nationwide retrospective analysis to establish a uniform protocol with international reference to be adopted in Egypt.

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.

Position paper: Rationale for the treatment of Wilms tumour in the UMBRELLA SIOP-RTSG 2016 protocol

The Renal Tumour Study Group of the International Society of Paediatric Oncology (SIOP-RTSG) has developed a new protocol for the diagnosis and treatment of childhood renal tumours, the UMBRELLA SIOP-RTSG 2016 (the UMBRELLA protocol), to continue international collaboration in the treatment of childhood renal tumours. This protocol will support integrated biomarker and imaging research, focussing on assessing the independent prognostic value of genomic changes within the tumour and the volume of the blastemal component that survives preoperative chemotherapy. Treatment guidelines for Wilms tumours in the UMBRELLA protocol include recommendations for localized, metastatic, and bilateral disease, for all age groups, and for relapsed disease. These recommendations have been established by a multidisciplinary panel of leading experts on renal tumours within the SIOP-RTSG. The UMBRELLA protocol should promote international collaboration and research and serve as the SIOP-RTSG best available treatment standard.

Bilateral Wilms tumour: a review of clinical and molecular features

Wilms tumour (WT) is the most common paediatric kidney cancer and affects approximately one in 10 000 children. The tumour is associated with undifferentiated embryonic lesions called nephrogenic rests (NRs) or, when diffuse, nephroblastomatosis. WT or NRs can occur in both kidneys, termed bilateral disease, found in only 5-8% of cases. Management of bilateral WT presents a major clinical challenge in terms of maximising survival, preserving renal function and understanding underlying genetic risk. In this review, we compile clinical data from 545 published cases of bilateral WT and discuss recent progress in understanding the molecular basis of bilateral WT and its associated precursor NRs in the context of the latest radiological, surgical and epidemiological features.

[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.

CT and MRI imaging features and long-term follow-up of adult Wilms' tumor

BACKGROUND

Only few previous case reports have been found focusing on the imaging findings of adult Wilms' tumor (WT).

PURPOSE

To characterize multislice computed tomography (MSCT), magnetic resonance imaging (MRI) characteristics, and follow-up results of adult WT.

MATERIAL AND METHODS

Sixteen patients with WT were studied retrospectively. MSCT and MRI were undertaken to investigate the tumor characteristics.

RESULTS

Tumors (mean diameter, 13.1 ± 4.5 cm) exhibited an expansible appearance and disrupted the reniform contour (16/16), cystic components (16/16), curvilinear calcification (1/16), poorly marginated (2/16), hemorrhage (16/16), displacement of renal pelvis or calyx (13/16), and had lymph node or distal metastases (5/16). Attenuation of WT was less or equal compared to renal parenchyma on unenhanced CT (P > 0.05), while tumor enhancement after administration of a contrast agent was lower than that of normal renal parenchyma (P < 0.05). WT was isointense on T1-weighted (T1W) imaging, isointense or hypointense on T2-weighted (T2W) imaging. Tumor enhancement was less than normal renal cortex in all phases (P < 0.05). The number of tumor stages (grades I, II, III, and IV) was two, three, six, and five cases, respectively. Follow-up time was in the range of 19-123 months; six patients died within 3 years, six patients died within 5 years after the initial diagnosis, with the remaining patients still alive.

CONCLUSION

Adult WT tends to be a large tumor, isointense or hypointense on T2W imaging with enhancement less than normal renal parenchyma in all phases. The long-term follow-up results demonstrated the poor prognosis of the tumor.

Clinical features and long-term outcomes of bilateral Wilms tumor treated with Taiwan Pediatric Oncology Group protocols: A single center report

AIMS

Wilms tumor (WT) is rare in Asia. Treatment of bilateral WT is challenging, and the treatment outcome of bilateral WT is rarely reported in low incidence areas.

METHODS

We enrolled patients with bilateral WT registered in Chang Gung Memorial Hospital, Taoyuan, Taiwan, between January 1986 and June 2015. They were treated according to the Taiwan Pediatric Oncology Group (TPOG) protocols. The clinical features and long-term outcomes were analyzed.

RESULTS

Six patients with histologically-proved bilateral WT were identified for analysis. One additional patient who was diagnosed with unilateral WT-associated intralobar nephrogenic rest, in addition to two small lesions in the contralateral kidney, was also included. There were total of three male patients and four female patients. The median follow-up period was 19 years (range 8-29 years). Five patients underwent initial biopsy and preoperative chemotherapy followed by surgery, whereas two patients underwent initial surgery followed by adjuvant chemotherapy. Local recurrence was found in two patients. The 8-year event-free survival and overall survival rates were 71.4% and 100%, respectively. Two patients developed advanced stage of chronic kidney disease, but none had been diagnosed with secondary malignant neoplasm. Other health issues such as hypertension, scoliosis and unspecified autoimmune disease were also found.

CONCLUSIONS

The treatment outcome in this study is comparably superior to other western countries. However, survivors of bilateral WT still have many chronic health issues and thereby need individualized long-term medical care.

Management of bilateral Wilms tumor over three decades: The perspective of a single center

INTRODUCTION

Outcomes of Wilms tumor improved in last 50 years and excellent survival rates can be achieved especially in case of non-metastatic disease and favorable histology. Nevertheless, bilateral cases still stand as a therapeutic challenge. Prognosis of bilateral Wilms tumor (BWT) is not as good as the unilateral tumors of similar stage and histology in terms of survival and renal function.

OBJECTIVE

Management of BWT is constantly evolving and still stands as a therapeutic challenge. This study is designed to review and share our experiences on this topic from a surgical standpoint.

STUDY DESIGN

The records of patients treated in our clinic between 1980 and 2013 according to Turkish Pediatric Group of Oncology protocol were analyzed retrospectively and clinical data, surgical details, pathology results, long term outcomes were analyzed.

RESULTS

Thirteen girls and 7 boys with a mean age of 2,5 years were treated. There were 2 patients with Wilms tumor-Aniridia-Growth Retardation complex and one with isolated hemihypertrophy. Metastasis were detected in lungs of 4 patients; liver of 2 and in the cranium of one. All patients except one with the presumptive diagnosis of unilateral Wilms tumor were given preoperative chemotherapy. To sum up; 19 nephroureterectomies, 8 partial nephrectomies and 13 enucleations were performed to 36 kidneys without any major early or late postoperative complications. Pathologic results revealed positive surgical margins in 2 lesions with enucleation and in 2 with partial nephrectomies and anaplasia in 4 patients. Two patients were not operated due to parental disapproval. Two patients had the need of dialysis; one was anephric and the others' renal functions recovered over a year. Seven patients received radiotherapy for pulmonary metastasis, positive surgical margins or local recurrences. Overall, 13 patients survived and 7 died due to metastasis, recurrences, and complication of dialysis and refusal of surgical treatment. Survival among all patients was 65% and 72.2% among operated ones. Of the 7 patients with the partial nephrectomy, 2 died and 5 survived. Among enucleation group, 8 out of 10 survived and 2 died. Survival was slightly higher among enucleation group (80% vs 71.4%). Median time of follow-up for survivors of disease is 5.8 years (min: 6 months and max: 14 years).

DISCUSSION

Outcomes of BWT management have changed dramatically during the last few decades from only survival, to a long life expectancy without the need of renal replacement therapy owing to improvements in treatment options. We argue that positive surgical margins do not necessarily lead to local recurrence. For this reason it may be wiser to favor on more nephron sparing surgery than to achieve negative surgical margins. Adjuvant chemotherapy and radiotherapy may be adequate to prevent local recurrence. Also, survival did not differ significantly between different ways of nephron sparing surgeries, so it may be wiser to choose enucleation over partial nephrectomy which preserves more nephrons. Nephron-sparing surgery should have utmost importance despite the risk of positive margins. On the other hand, there is not enough data to interpret if positive surgical margins have role on distant metastases or not. Presence of metastasis and recurrence seems to be an important determinant of prognosis given the fact that none of the survivors had any metastasis or recurrence.

CONCLUSION

Nephron preservation should be the aim while taking positive surgical margin risk on nephron sparing surgery side relying on postoperative chemotherapy and carefully planned radiotherapy to avoid recurrence. However, there is significant diversity on the management BWT in different centers and a certain validated guideline or protocol to provide the optimal treatment is still lacking.

Experience with retroperitoneal partial nephrectomy in bilateral Wilms tumor

INTRODUCTION

Retroperitoneal partial nephrectomy has not been studied as a surgical approach for children with bilateral Wilms tumor. There are advantages to this technique, including isolation of urine leaks to the retroperitoneum, decreased risk of bowel injury, and decreased time to resuming a diet. Presently, all bilateral Wilms tumors are treated with neoadjuvant chemotherapy and attempted nephron-sparing surgery. In this study, we compare the outcomes of the retroperitoneal and transabdominal approaches in doing partial nephrectomy for bilateral Wilms tumor.

METHODS

With the institutional review board approval, we reviewed records of 14 pediatric patients with metachronous or synchronous bilateral Wilms tumors who underwent surgery after chemotherapy between 1994 and 2014. Only operative procedures with the intent to cure were included (n=15) and of these, 5 procedures were retroperitoneal and 10 were transabdominal in approach. Individual kidneys operated upon (n=26) were analyzed using the preoperative radius exophytic/endophytic nearness anterior/posterior location nephrometry score to ensure that resected tumors were comparable between the two surgical groups. Charts were retrospectively analyzed for intraoperative parameters and postoperative course. Differences between parameters were evaluated using Mann-Whitney and chi-square tests.

RESULTS

Resected tumors in both surgical treatment groups had comparable sizes, nephrometry scores, and rates of anaplasia. Operative time, blood loss, and transfusion requirement were similar between the two groups. The extent of lymph node sampling and rates of R0 resection were equivalent. One adverse intraoperative event, a bowel enterotomy, was seen in the transabdominal group. Patients after retroperitoneal partial nephrectomy required half the time to return to an oral diet as compared with those after a transabdominal surgery, approaching statistical significance (p=0.08). Rates of the postoperative urine leak were similar, though two in the transabdominal group required reoperation for drainage. There were four recurrences, all in the transabdominal group.

CONCLUSION

Our experience demonstrates that the retroperitoneal approach is equivalent to the transabdominal technique with regards to intraoperative complications, lymph node dissection, and R0 resection. Advantages include less time to resumption of oral feeding, decreased risk of bowel injury, and isolation of urine leaks to the retroperitoneum. It should be considered a viable surgical option in the treatment of bilateral Wilms tumors.

An approach to renal masses in pediatrics

Renal masses in children may be discovered during routine clinical examination or incidentally during the course of diagnostic or therapeutic procedures for other causes. Renal cancers are rare in the pediatric population and include a spectrum of pathologies that may challenge the clinician in choosing the optimal treatment. Correct identification of the lesion may be difficult, and the appropriate surgical procedure is paramount for lesions suspected to be malignant. The purpose of this article is to provide a comprehensive overview regarding the spectrum of renal tumors in the pediatric population, both benign and malignant, and their surgical management.

Management and outcomes in massive bilateral Wilms' tumors

Purpose:

To evaluate the outcome of children with bilateral Wilms’ tumor (BWT) treated on All India Institute of Medical Sciences-Wilms Tumor-99 (AIIMS-WT-99) protocol.

Materials and Methods:

All children with BWT, registered in our solid tumor clinic from August 1999 through December 2010 were included.

Results:

Of the 178 fresh cases of Wilms Tumor (WT) treated during this period, 11 (6.2%) had bilateral involvement. All patients except one (12 and 3 cm), had massive bilateral tumors of more than 10 cm on each side. There were eight boys and three girls in the age range 6–30 months. One patient had Denys-Drash syndrome. Twenty renal units were operated upon (12 tumorectomy, five partial nephrectomy, and three nephrectomies), while one patient with inferior vena cava (IVC) thrombus died of renal failure. Tumor spill occurred in three units, lymphnode was positive in two patients. Local recurrence occurred in four patients (six of 18 renal units (33%)—two bilateral and two unilateral). There was one recurrence in the liver that was treated with radio-frequency ablation. The 5-year overall survival (OS) was 90% (95% confidence interval (CI) = 50.8–98.6) and the relapse free survival (RFS) was 38% (95% CI = 6.1–71.6).

Conclusion:

Massive BWT respond poorly to preoperative chemotherapy, are often not amenable to partial nephrectomy/tumorectomy and have a higher local recurrence rate, giving a poor RFS.

The management of bilateral Wilms tumor

Wilms tumor (WT) is the most common malignant renal tumor in childhood. Approximately 5-7% of WT patients present with bilateral disease, either synchronously or metachronously. Bilateral WT usually occurs in younger children and more often in girls. Management of a child with bilateral WT is very challenging. In contrast to unilateral WT, there has not been uniform agreement about the therapeutic strategy in the management of bilateral WT. As surgery is a critical component in the treatment of WT, the aim is to achieve a high cure rate while maintaining adequate long-term renal function in patients with bilateral WT. In the past, radical surgical procedures which lead to the patients on dialysis have been traditionally recommended in these patients. After several multicentre trials, bilateral biopsies followed by pre-operative chemotherapy and then renal salvage surgery have been recommended. The management of bilateral WT has evolved from primary surgical extirpation to kidney-preserving resection after preoperative chemotherapy. Preoperative chemotherapy often results in significant reduction in tumor size, thereby facilitating subsequent renal salvage. The analysis of children with bilateral WT shows that preservation of renal parenchyma is possible following initial preoperative chemotherapy. Only centers with experience in bilateral WT should treat the cases with bilateral WT to provide optimal treatment.

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

BACKGROUND

Great improvements in diagnostics and treatment for malignant disease in childhood have led to a major increase in survival. However, childhood cancer survivors (CCS) are at great risk for developing adverse effects caused by multimodal treatment for their malignancy. Nephrotoxicity is one of these known (acute) side effects of several treatments, including cisplatin, carboplatin, ifosfamide, radiotherapy and nephrectomy, and can cause glomerular filtration rate impairment, proteinuria, tubulopathy and hypertension. However, evidence about the long-term effects of these treatments on renal function remains inconclusive. To reduce the number of (long-term) nephrotoxic events in CCS, it is important to know the risk of, and risk factors for, early and late renal adverse effects, so that ultimately treatment and screening protocols can be adjusted.

OBJECTIVES

To evaluate existing evidence on the effects of potentially nephrotoxic treatment modalities on the prevalence of and associated risk factors for 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 healthy controls or CCS treated without potentially nephrotoxic treatment.

SEARCH METHODS

We searched the following electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 4, 2011), MEDLINE/PubMed (from 1945 to December 2011) and EMBASE/Ovid (from 1980 to December 2011).

SELECTION CRITERIA

With the exception of 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 children and adults who were treated for a paediatric malignancy (aged 18 years or younger at diagnosis) with cisplatin, carboplatin, ifosfamide, radiation including the kidney region and/or a nephrectomy.

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

The search strategy identified 5504 studies, of which 5138 were excluded on the basis of title and/or abstract. The full-text screening of the remaining 366 articles resulted in the inclusion of 57 studies investigating the prevalence of and sometimes also risk factors for early and late renal adverse effects of treatment for childhood cancer. The 57 studies included at least 13,338 participants of interest for this study, of whom at least 6516 underwent renal function testing. The prevalence of renal adverse effects ranged from 0% to 84%. This variation may be due to diversity in included malignancies, prescribed treatments, reported outcome measurements and the methodological quality of available evidence.Chronic kidney disease/renal insufficiency (as defined by the authors of the original studies) was reported in 10 of 57 studies. The prevalence of chronic kidney disease ranged between 0.5% and 70.4% in the 10 studies and between 0.5% and 18.8% in the six studies that specifically investigated Wilms' tumour survivors treated with a unilateral nephrectomy.A decreased (estimated) glomerular filtration rate was present in 0% to 50% of all assessed survivors (32/57 studies). Total body irradiation; concomitant treatment with aminoglycosides, vancomycin, amphotericin B or cyclosporin A; older age at treatment and longer interval from therapy to follow-up were significant risk factors reported in multivariate analyses. Proteinuria was present in 0% to 84% of all survivors (17/57 studies). No study performed multivariate analysis to assess risk factors for proteinuria.Hypophosphataemia was assessed in seven studies. Reported prevalences ranged between 0% and 47.6%, but four of seven studies found a prevalence of 0%. No studies assessed risk factors for hypophosphataemia using multivariate analysis. The prevalence of impairment of tubular phosphate reabsorption was mostly higher (range 0% to 62.5%; 11/57 studies). Higher cumulative ifosfamide dose, concomitant cisplatin treatment, nephrectomy and longer follow-up duration were significant risk factors for impaired tubular phosphate reabsorption in multivariate analyses.Treatment with cisplatin and carboplatin was associated with a significantly lower serum magnesium level in multivariate analysis, and the prevalence of hypomagnesaemia ranged between 0% and 37.5% in the eight studies investigating serum magnesium.Hypertension was investigated in 24 of the 57 studies. Reported prevalences ranged from 0% to 18.2%. A higher body mass index was the only significant risk factor noted in more than one multivariate analysis. Other reported factors that significantly increased the risk of hypertension were use of total body irradiation, abdominal irradiation, acute kidney injury, unrelated or autologous stem cell donor type, growth hormone therapy and older age at screening. Previous infection with hepatitis C significantly decreased the risk of hypertension.Because of the profound heterogeneity of the studies, it was not possible to perform any meta-analysis.

AUTHORS' CONCLUSIONS

The prevalence of renal adverse events after treatment with cisplatin, carboplatin, ifosfamide, radiation therapy involving the kidney region and/or nephrectomy ranged from 0% to 84%. With currently available evidence, it was not possible to draw any conclusions with regard to prevalence of and risk factors for renal adverse effects. Future studies should focus on adequate study design and reporting and should deploy multivariate risk factor analysis to correct for possible confounding. Until more evidence becomes available, CCS should be enrolled into long-term follow-up programmes to monitor their renal function and blood pressure.

Bilateral Wilms' tumour in a developing country: a descriptive study

PURPOSE

To present our experience of 20 children with bilateral Wilms' tumour seen in a resource-challenged environment over a 10-year period.

METHOD

All patients with a diagnosis of bilateral synchronous Wilms' tumour were identified and recruited.

RESULTS

Study patients represented 11 % of a cohort of 177 new patients with Wilms' tumour seen over the same period. Three patients had a syndromic predisposition to Wilms' tumour. Metastatic disease was seen at presentation in four patients (20 %) and three children presented with unilateral tumour rupture. One patient presented with paraplegia and one with obstruction of the duodenum. All children received neoadjuvant chemotherapy. One HIV-infected child died of IRIS after neoadjuvant treatment, but before surgery. One child died of progressive disease after unilateral nephrectomy. Nephron-sparing surgery was performed in 22 kidneys and 15 kidneys were removed in toto. Following enucleation of tumours, three children had positive margins. Discordant histopathology was seen in 53 % of patients. Overall survival at 2 years is 85 %.

CONCLUSION

Despite significant co-morbidity and advanced disease, bilateral Wilms' tumour is a treatable disease in a resource-constrained environment.

The EKZ/AMC childhood cancer survivor cohort: methodology, clinical characteristics, and data availability

PURPOSE

Childhood cancer survivors are at high risk of late adverse effects of cancer treatment, but there are still many gaps in evidence about these late effects. We described the methodology, clinical characteristics, data availability, and outcomes of our cohort study of childhood cancer survivors.

METHODS

The Emma Children's Hospital/Academic Medical Center (EKZ/AMC) childhood cancer survivor cohort is an ongoing single-center cohort study of ≥5-year childhood cancer survivors, which started in 1996 simultaneously with regular structured medical outcome assessments at our outpatient clinic.

RESULTS

From 1966 to 2003, 3,183 eligible children received primary cancer treatment in the EKZ/AMC, of which 1,822 (57.2 %) survived ≥5 years since diagnosis. Follow-up time ranged from 5.0 to 42.5 years (median, 17.7). Baseline primary cancer treatment characteristics were complete for 1,781 (97.7 %) survivors, and 1,452 (79.7 %) survivors visited our outpatient clinic. Baseline characteristics of survivors who visited the clinic did not differ from those without follow-up. Within our cohort, 54 studies have been conducted studying a wide range of late treatment-related effects.

CONCLUSIONS

The EKZ/AMC childhood cancer survivor cohort provides a strong structure for ongoing research on the late effects of childhood cancer treatment and will continuously contribute in reducing evidence gaps concerning risks and risk groups within this vulnerable population.

IMPLICATIONS FOR CANCER SURVIVORS

Our large cohort study of childhood cancer survivors with complete baseline characteristics and unique, long-term medical follow-up decreases gaps in evidence about specific risks of late effects and high-risk groups, with the ultimate goal of improving the quality of care for childhood cancer survivors.

Bilateral Wilms tumors (WT) treated with the SIOP 93 protocol in France: epidemiological survey and patient outcome

BACKGROUND

The treatment of bilateral Wilms tumors (WT) requires multimodality therapy with individualized decision to ensure cure while preserving as much renal parenchyma as possible.

PROCEDURE

We analyzed the clinical records of 49 children with bilateral WT treated in France between 1993 and 2001, according to the SIOP-93 guidelines (individual treatment program: Treatment was continued as long as there was imaging evidence of tumor regression). Pathology reports, duration of preoperative chemotherapy and surgical records were also reviewed. Overall Survival (OS) and Event-Free Survival (EFS) rates were studied and relationships between possible prognostic factors and survival were assessed.

RESULTS

Imaging studies revealed bilateral involvement in 98% of the cases. Whatever the response to preoperative chemotherapy, the mean duration of neoadjuvant chemotherapy was 80 days (Q1-Q3: 47-89 days). Forty-eight children underwent nephron sparing surgery (NSS) at least for one kidney and 19 for both. Five-year EFS and OS rates were, respectively, 83.4 and 89.5%. Only the most advanced stages were shown to affect OS (P = 0.03). At study endpoint, end-stage renal disease (ESRD) was reported in seven children, associated with a predisposing phenotype in three.

CONCLUSIONS

Results of this study demonstrate a favorable outcome of patients with bilateral WT receiving an individual treatment program. With a tailored approach to treatment according to the tumor response, 77% of our patients were operated before the third month of preoperative chemotherapy. In spite of good survival, 14% of our patients have ESRD.

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.

Bilateral renal cell carcinoma in a child

Renal cell carcinoma is a rare renal tumor in the pediatric population with an incidence of 0.1-0.3%. We report on the first case of bilateral renal clear cell carcinoma that was treated by partial nephrectomies. We performed a complete genetic evaluation to exclude a family inheritance and we looked at the deletions associated with the possible histologic subtypes of renal cell carcinoma. The patient had no evidence of recurrence after 80-month follow-up and her renal function remained normal.