Treatment of bilateral Wilms' tumor: comparison of initial biopsy and chemotherapy to initial surgical resection in the preservation of renal mass and function

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

Context:

Synchronous Bilateral Wilms tumor (sBWT).

Aims:

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

Settings and Design:

Retrospective and prospective randomized study.

Subjects and Methods:

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

Statistical Analysis Used:

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

Results:

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

Conclusions:

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

Clinical features, treatment, and outcomes of bilateral Wilms' tumor: A systematic review and meta-analysis

BACKGROUND

Wilms' tumor(WT) is the most common malignant renal tumor of childhood. Despite the good prognosis of WT, bilateral Wilms' tumor (BWT) still has a poor outcome. We systematically reviewed the literature on BWT, aiming to define its clinical features, treatment, and outcomes.

METHODS

PubMed, OVID EMbase, Web of Science, and Cochrane Library were systematically searched for studies published from 1980 to 2017. Case series and comparative studies reported clinical data of BWT patients were included.

RESULTS

A total of 32 studies comprising 1457 patients were retained for primary outcome. Hemihypertrophy, cryptorchidism, and Beckwith-Wiedemann syndrome(BWS) are the most common congenital anomalies and syndrome. 86% of patients had favorable histology (FH). Patients with local stage I or II accounted for 64%, and 12.6% had metastasis at diagnosis. Bilateral nephron-sparing surgery (NSS) was achieved in 33.8%. Recurrence and renal failure occurred in 20% and 8%. The overall survival (OS) was 73%. In comparative studies, OS of patients undergoing bilateral NSS was similar to that of other operation types.

CONCLUSION

Prognosis of BWT has been improved but is significantly poorer than WT. Bilateral NSS was recommended by most centers to preserve more renal volume. However, finding a balance between retaining renal function and avoiding recurrence remains a question.

TYPE OF STUDY

Systematic review.

LEVEL OF EVIDENCE

Level IV.

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.

Nephron-sparing surgery for Wilms tumor: A systematic review

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Efficacy of Preoperative Chemotherapy in Treatment of Children With Wilms' Tumor: A Meta-Analysis

Context:

To assess the efficacy of preoperative chemotherapy in Wilms’ tumor patients and explore its true value for specific subgroups.

Objectives:

In the presence of these controversies, a meta-analysis that examines the efficacy of preoperative chemotherapy in Wilms’ tumor patients and specific subgroups is needed to clarify these issues. The objective of this meta-analysis is to assess the efficacy of preoperative chemotherapy in Wilms’ tumor patients and explore its true value for specific subgroups.

Data Sources:

Computer-based systematic search with “preoperative chemotherapy”, “Neoadjuvant Therapy” and “Wilms’ tumor” as search terms till January 2013 was performed.

Study Selection:

No language restrictions were applied. Searches were limited to randomized clinical trials (RCTs) or retrospective studies in human participants under 18 years. A manual examination of references in selected articles was also performed.

Data Extraction:

Relative Risk (RR) and their 95% Confidence Interval (CI) for Tumor Shrinkage (TS), total Tumor Resection (TR), Event-Free Survival (EFS) and details of subgroup analysis were extracted. Meta-analysis was carried out with the help of the software STATA 11.0. Finally, four original Randomized Clinical Trials (RCTs) and 28 retrospective studies with 2375 patients were included.

Results:

For preoperative chemotherapy vs. up-front surgery (PC vs. SU) group, the pooled RR was 9.109 for TS (95% CI: 5.109 - 16.241; P < 0.001), 1.291 for TR (95% CI: 1.124 - 1.483; P < 0.001) and 1.101 for EFS (95% CI: 0.980 - 1.238; P = 0.106). For subgroup short course vs. long course (SC vs. LC), the pooled RR was 1.097 for TS (95% CI: 0.784 - 1.563; P = 0.587), 1.197 for TR (95% CI: 0.960 - 1.493; P = 0.110) and 1.006 for EFS (95% CI: 0.910 - 1.250; P = 0.430).

Conclusions:

Short course preoperative chemotherapy is as effective as long course and preoperative chemotherapy only benefits Wilms’ tumor patients in tumor shrinkage and resection but not event-free survival.

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.

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

OBJECTIVE

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Bilateral Wilms' tumors: single-center experience with 22 cases and literature review

OBJECTIVES

Bilateral Wilms' tumors represent a therapeutic challenge. The primary aim of management is eradication of the neoplasm and preservation of renal function. We present our experience in the management of such cases in a single-center experience.

METHODS

This was a retrospective study of 22 patients with histologically proven bilateral nephroblastoma who were treated from 1993 to 2008 at our center. Of the 22 patients, 12 were girls and 10 were boys, with a median age of 3 years (range 1-9); 19 had a synchronous presentation and 3 a metachronous presentation. Of the 22 patients, 6 underwent initial surgical resection followed by chemotherapy and 16 underwent initial biopsy and preoperative chemotherapy. The final oncologic and renal outcomes were assessed.

RESULTS

The median follow-up period was 3 years (range 1-11). Of the 22 patients, 8 died, for an overall survival rate of 63.5%. The survival for the initial chemotherapy and initial surgery groups was essentially similar. Of all the variables studied, unfavorable histologic findings had a significant negative effect on survival. Of the 5 patients with unfavorable histologic findings, 4 died during the follow-up period. The median volume of preserved renal parenchyma was 40%. All patients had good renal function during follow-up, except for 1 patient who had undergone bilateral nephrectomy.

CONCLUSIONS

Bilateral Wilms' tumors impose 2 conflicting issues: elimination of the pathology and preservation of the renal function. Currently, treatment regimens involving initial chemotherapy followed by conservative surgery can achieve these goals in an important proportion of patients.

Renal function and outcome following salvage surgery for bilateral Wilms' tumor

PURPOSE

Maintaining adequate renal function without compromising cure in children with bilateral Wilms' tumor is surgically demanding and challenging. The aim of this study was to assess renal function and outcome in children treated in one institution for bilateral Wilms' disease by renal salvage procedures.

METHODS

This study is a retrospective review of all patients with histologically proven bilateral nephroblastoma who underwent a renal salvage procedure between November 1973 and June 2002. The median follow-up time was 52 months (range, 8 to 326 months).

RESULTS

Twenty-three patients were included in the study. The median age at diagnosis was 19 months (range, 5 to 65 months). Patients who presented before 1982 (n = 5) were treated surgically first followed by chemotherapy. The remainder (n = 18) received initial chemotherapy before the operation. Of the 46 kidneys, 18 had a nephrectomy. The remaining 28 underwent a renal salvage procedure. At follow-up, 19 patients had good renal function, 2 had satisfactory function, and 2 had renal failure. Seventeen of the 23 children are alive and tumor free at follow-up (74%). Four children died of distant metastases and 2 of renal failure. Local recurrence in the salvaged kidney was detected in 1 patient 12 years after surgery after the commencement of immunosuppression for renal transplantation.

CONCLUSIONS

These results confirm that renal salvage procedures, in combination with chemotherapy, are a safe and effective way of treating children with bilateral Wilms' disease. In addition, renal salvage surgery can maintain satisfactory renal function in the majority of these patients without an increased risk of local recurrence. When transplantation is required, the remaining native kidney should be removed to prevent tumor recurrence.

Risk-based management: current concepts of treating malignant solid tumors of childhood

BACKGROUND

Improved survival with pediatric malignancies has been positively influenced by multidisciplinary cooperative studies using surgery, chemotherapy, and radiation therapy, but one-third of all children with cancer succumb to their condition. The identification of biologic and genetic characteristics as risk factors for the various tumors has led to changes in treatment using risk-based management as the template for care.

STUDY DESIGN

The purpose of this report is fourfold: (1) to review survival data concerning three solid malignant tumors of childhood (Wilms' tumor, rhabdomyosarcoma, and neuroblastoma), (2) to describe important prognostic genetic and biologic risk factors for each tumor, (3) to update changes in staging criteria, and (4) to familiarize the reader with the concept of risk-based management, which individualizes treatment in an attempt to maximize survival and minimize longterm morbidity.

RESULTS

The overall survival rates for Wilms' tumor, rhabdomyosarcoma, and neuroblastoma are currently 90%, 70%, and 40%, respectively. Most patients with Wilms' tumor have favorable histology and survive after nephrectomy and chemotherapy, but 10% have poor prognostic variables, including unfavorable (anaplastic) histology, chromosomal loss on 1p and 16q, and diploidy. Instances of lung or liver metastases, major tumor spillage during resection, remote lymph node involvement, and bilateral tumors have worse outcomes. Rhabdomyosarcoma is associated with chromosomal translocation of t(2:13) in alveolar types, the p53 tumor suppressor gene, and 11p15. Survival is dependent on the tumor site and pretreatment clinical group. Orbit, paratesticular, vulvar, and vaginal tumors have a good prognosis, but other genitourinary tumors, extremity and trunk lesions, and parameningeal head and neck tumors have a worse prognosis. Survival rates by clinical group are stage I, 93%; II, 81%; III, 73%; and IV, 30%. Resectability, lymph node involvement, DNA ploidy, and pretreatment TNM staging affect outcomes. Neuroblastoma is an embryonal tumor with bizarre behavior and can regress, mature, or rapidly progress. Most patients have advanced disease at diagnosis. Neuroblastoma is associated with loss of heterozygosity on chromosome 1p36 and occasionally deletions on 14q and 17q. Survival is affected by age and stage (at less than 1 year, stages I [95% to 100%], II [85% to 90%], and IV-S [more than 80%] do better) and other risk factors. Patients with advanced disease (older than 1 year, stage III [70%], and stage IV [12%]) often have amplification of the N-myc oncogene, diploid tumors, 1p36 deletion, and unfavorable histology and fare worse.

CONCLUSIONS

On the basis of these data, children with solid tumors are currently categorized into low-, intermediate-, and high-risk groups. Newer protocols individualize treatment using risk factors as predictors of outcomes. Risk-based management allows the clinician to weigh the risks and benefits of treatment for each patient to maximize survival, minimize longterm morbidity, and improve the quality of life.

Nephron-sparing surgery in synchronous bilateral Wilms' tumors

BACKGROUND

Synchronous bilateral Wilms' tumor is rare and experience with renal salvage procedures and their limitations accumulates slowly at single institutions. The authors analyzed whether their growing experience with atypical renal resections and awareness of nephroblastomatosis had influenced the outcome of surgical procedures.

METHODS

Retrospective analysis of patients treated from 1977 to 1995 was performed. Surgical reports, clinical sheets, and follow-up data were evaluated. All pathology slides were reviewed for histological classification and presence of nephroblastomatosis. Renal function was evaluated pre- and postoperatively and at final follow-up.

RESULTS

Fourteen patients were treated. Two to 20 years after surgery, 13 patients are alive, and none has had renal failure. Five patients had unilateral nephrectomies, and a renal salvage procedure was performed on 22 kidneys. One patient with an anaplastic bilateral Wilms' tumor died of tumor progress 1 year after surgery. Several kidneys, which would have been sacrificed by application of traditional criteria, could be salvaged by atypical and unconventional tumor resections and by superficial dissection and enucleation of supposed nephroblastomatosis. Nephrectomy appeared unavoidable with hilar invasion by tumor.

CONCLUSION

Atypical resections of localized lesions and superficial dissections of suspected nephroblastomatosis appeared as valid surgical treatment options for patients who would otherwise have been candidates for nephrectomy. In the case of hilar tumor invasion, however, nephrectomy seems unavoidable.

Bilateral Wilms' tumor: a clinicopathologic review

Bilateral Wilms' tumor occurs at a younger age than unilateral disease. While it generally has a good prognosis, it presents a therapeutic dilemma to balance curative surgical resection with preservation of renal tissue. A 15 year review of bilateral Wilms' tumors diagnosed at Princess Margaret Hospital was undertaken. Of 46 Wilms' tumor cases, eight were designated bilateral by diagnostic imaging (median age 1.1 years compared with 3.5 years for unilateral tumors). The surgical management entailed primary nephrectomy with contralateral biopsy in two patients, and bilateral biopsy and delayed resection in all remaining surviving patients (one patient died of perioperative complications). Seven patients had localized disease (stage I/II) and the six surviving patients received chemotherapy with vincristine and actinomycin; no patient received radiotherapy. All are alive and well (median follow-up 5.1 years). The remaining patient presented with pulmonary metastases and died of disease progression. Pathologic review revealed that four patients had truly bilateral disease demonstrable by histology, three had unilateral Wilms' tumor with contralateral nephrogenic rests, and in one patient the biopsies of the contralateral kidney showed neither tumor nor nephrogenic rests. In most cases pathological material was subject to external review. Follow-up demonstrates excellent renal function with compensatory hypertrophy in the remaining renal tissue. Conservative surgery and simple out-patient based, low toxicity chemotherapy is curative in most patients.

Conservative surgical management of bilateral Wilms tumor: results of the United Kingdom Children's Cancer Study Group

PURPOSE

Bilateral Wilms tumor presents the clinician with a treatment dilemma. Since 1980 most centers of the United Kingdom Children's Cancer Study Group have used a conservative surgical approach with initial biopsy followed by chemotherapy and delayed surgical resection. We assess the outcome of this treatment approach in terms of survival, and preservation of renal mass and function.

MATERIALS AND METHODS

We retrospectively analyzed the records of 71 children with bilateral Wilms tumor diagnosed between 1980 to 1995 at 17 United Kingdom Children's Cancer Study Group centers. In 57 patients conservative surgical treatment with initial biopsy was followed by chemotherapy and delayed tumor resection, while 13 underwent initial surgical resection followed by chemotherapy. One patient was excluded from study because the lesion in 1 kidney proved to be a benign cyst. Mean followup was 6 years (range 1 to 15). The percentage of renal tissue involved with tumor and preserved was estimated, and renal function at the last followup was recorded.

RESULTS

Overall survival was 69% with similar survival in the conservatively treated and initial surgical resection groups. At the last followup renal function was normal in 80% of the patients in each group. Mean preserved renal mass was 45 and 35% in the conservatively treated and initial resection groups, respectively, with a trend toward better preservation in those treated conservatively. Bilateral Wilms tumor with an unfavorable histology was associated with a poor prognosis.

CONCLUSIONS

Conservative surgical treatment of favorable histology bilateral Wilms tumor may improve the preservation of renal mass and function without impairing patient survival.

Long-term renal function in patients with irradiated bilateral Wilms tumor. National Wilms' Tumor Study Group

The treatment of bilateral Wilms tumor (BWT) involves a multidisciplinary approach including surgery, chemotherapy, and radiation therapy. The long-term renal function in patients receiving all three treatment modalities has not been evaluated. Long-term renal function was evaluated in 81 children with synchronous BWT who received radiation therapy as part of their treatment. Renal function was assessed by measuring blood urea nitrogen (BUN) and serum creatinine (Cr). The normal range for the BUN was defined as 10-24 mg/dl, and the Cr was considered normal at levels of <1.5 mg/dl. Moderate elevations were defined as a BUN of 25-50 mg/dl and/or a Cr of 1.6-2.5 mg/dl and marked elevations as a BUN of >50 mg/dl and/or a Cr of >2.5 mg/dl. BUN and Cr levels were measured prior to treatment and at the following intervals: 6 months after treatment, 1 year after treatment, 2 years after treatment, and at last follow-up. Any elevation during the posttreatment follow-up period was considered abnormal. A total of 28 children (34.6%) had elevated BUN and/or Cr levels, and 18 had moderate and 10 had marked renal insufficiency. No dose-response relationship was established when comparing the radiation doses of those with elevated values to those with normal values. The renal complication rate was moderate, and other factors including surgery, extent and nature of chemotherapy, and recurrent tumor must also be taken into account. The elevations present in several children could be attributed to tumor recurrence and in one case to gentamicin toxicity. The management of children with BWT should consider all of these risks, and attempts to preserve renal parenchyma are warranted.

Wilms' tumor

Wilms' tumor is the most common renal malignancy of childhood. Survival rates for favorable histology of Wilms' tumor currently approach 90%. Recent advances in the molecular genetics of Wilms' tumor have led to insights into the genetic factors involved in the development of Wilms' tumor, normal renal development, and the mechanisms of tumorigenesis.

Bilaterally multicentric synchronous Wilms' tumor: successful conservative treatment despite persistence of nephrogenic rests

We report a case of synchronous bilateral Wilms' tumor in a girl with incomplete Beck-with-Wiedemann syndrome and hemihypertrophy. Multiple small tumors were present in both kidneys. The initial diagnostic biopsy showed stage I monophasic blastematous Wilms' tumor of favorable histology, with multiple perilobar nephrogenic rests (nephroblastomatosis). By flow cytometry, tumor was diploid, with an S-phase fraction of 13.9%. Dactinomycin and vincristine were begun as per the National Wilms' Tumor Study IV (18 week course). After 1 month, only a single small lesion was evident, which persisted unchanged. Excisional biopsy 5 months after beginning chemotherapy showed entirely necrotic tumor but apparently unaltered nephrogenic rests. After completing chemotherapy, the child has done well, with normal renal function and no evidence of disease 3 years after diagnosis. Management of stage V Wilms' tumor is tailored to the individual case, being as conservative as possible to spare renal parenchyma. Given the high incidence of coexisting nephrogenic rests in bilateral Wilms' tumor, careful follow-up is required, as these potentially premalignant rests may resist chemotherapy.

Local control in synchronous bilateral Wilms tumor

PURPOSE

To evaluate the role of radiation therapy (RT), chemotherapy (CT), and surgery in the local control of synchronous bilateral Wilms Tumor (WT).

METHODS AND MATERIALS

Between 1962 to 1993, 45 children were treated for bilateral WT; 38 patients with synchronous tumors were reviewed. Initial surgery depended on the era of treatment and included unilateral nephrectomy (N)/partial nephrectomy (PN) and contralateral PN in 6, unilateral N/PN alone in 7, and biopsy only in 25. Chemotherapy (CT) consisted of vincristine, actinomycin-D, and adriamycin in 32 and vincristine/ actinomycin-D in 6. Radiation therapy (RT) was given to 32 patients. Treatment included both kidneys in 20, unilateral kidney plus contralateral renal bed in 9, unilateral kidney in 2, and unilateral renal bed in 1. Follow-up was 16 months to 25 years (median: 6.3 years).

RESULTS

Local control (LC) has been maintained in 66 out of 76 sites (87%). For Stage I-II disease with initial N/PN, LC was 10 out of 12 with RT and 11 out of 11 without RT; for Stage III with initial N/PN, LC was 8 out of 9 with RT and 1 out of 1 without RT. Initial CT and RT was followed by delayed N/PN for 20 sites; LC was 15 out of 17 in post induction Stage I-II and 1 out of 3 in postinduction Stage III. In 23 sites undergoing biopsy and chemotherapy, LC was 19 out of 20 with RT and 1 out of 3 without RT. Seven of 23 sites had a complete response (CR) after induction CT, and LC was maintained in four out of four with RT and one out of three without RT. Univariate Cox Regression analysis demonstrated that sites receiving two drugs had a statistically significant increase in loco-regional relapse when compared to sites receiving three drugs (p = 0.004). Major morbidities related to multimodality therapy have included renal failure in one patient and small bowel obstruction requiring lysis of adhesions in two patients.

CONCLUSIONS

Local control does not seem to be compromised by renal conservation therapy. Local control is excellent in sites treated with radiation therapy in combination with three drug chemotherapy.

Renal salvage procedures in patients with synchronous bilateral Wilms' tumors: a report from the National Wilms' Tumor Study Group

Synchronous bilateral Wilms' tumor accounts for 4% to 6% of all Wilms' tumors. Renal salvage procedures (partial nephrectomy and enucleation) have been recommended to conserve renal parenchyma. The objective of this study was to review the results of renal salvage operations performed in children who had bilateral neoplasms. The authors reviewed the records of 98 children enrolled in the Fourth National Wilms' Tumor Study who had synchronous bilateral tumors and underwent renal salvage procedures. One hundred thirty-four kidneys were managed with renal salvage procedures. Complete excision of gross disease was accomplished in 118 (88%) of the 134 kidneys. Local tumor recurrence in the remnant kidney or tumor bed occurred in 11 cases (8.2%). Overall, 72% of the kidneys were preserved, and the 4-year survival rate was 81.7%. The surgical morbidity after a salvage procedure was comparable to that of a complete nephrectomy in patients with unilateral Wilms' tumor. Although the incidence of positive surgical margins is worrisome, it did not invariably lead to local recurrence in the remnant kidney or the tumor bed.

Needle track recurrence after biopsy of non-metastatic Wilms tumour

A 2-year-old girl presented with a left-sided Wilms tumour. She was randomised to have a needle biopsy and preoperative chemotherapy according to the United Kingdom Children's Cancer Study Group (UKCCSG) protocol, a trial of preoperative chemotherapy in biopsy-proven Wilms tumour versus immediate nephrectomy (UK 9101). A nephrectomy was performed 6 weeks later. Six months later she presented with an abdominal wall recurrence at the needle biopsy site, which was resected. The value of needle biopsy in localised Wilms tumour is debated.

Renal failure in Wilms' tumor patients: a report from the National Wilms' Tumor Study Group

This report defines the incidence and determines the etiology of renal failure (RF) in patients undergoing treatment for Wilms' tumor (WT). The database of the National Wilms' Tumor Study (NWTS) was searched to identify all children reported to have developed chronic renal failure. There were 55 patients found to have RF. Of these, 39 patients had bilateral tumors, 15 with unilateral disease and one with a WT in a solitary kidney. The median interval from diagnosis to the onset of renal failure was 21 months. The incidence of RF in bilateral WT was 16.4% for NWTS-1 & -2, 9.9% for NWTS-3, and 3.8% for NWTS-4. The incidence of RF in unilateral WT remained stable. The most common etiologies of RF were: bilateral nephrectomy for persistent or recurrent tumor (24 pts), Drash syndrome (12 pts), progressive tumor in the remaining kidney (5 pts), radiation nephritis (6 pts), and other causes (5 pts). The etiology of renal failure was not reported in three children. Children with unilateral WT and a normal contralateral kidney have a very low incidence of RF, and this review does not support a recommendation for parenchymal sparing procedures in these patients. Children with bilateral WT are at risk for the development of RF, and parenchymal sparing procedures are warranted.

Bilateral Wilms' tumor: in situ cooling of the kidney facilitates curative excision of tumors, with preservation of renal function

Bilateral synchronous multifocal Wilms' tumor is a rare malignancy for which no optimum treatment has been established thus far. The need to preserve renal parenchyma whenever possible is obvious. The authors describe a patient who underwent removal of six subcapsular tumors from a kidney that had been protected from ischemia by in situ cooling with UW-Belzer solution and by surface cooling. This technique was safe, easy to perform, and allowed all the time required to resect the tumors under adequate visual control and to wait for analysis of the frozen sections. It might be a useful alternative to the more complicated "bench" technique.

Preoperative chemotherapy for mesoblastic nephroma

A neonate with extensive stage III mesoblastic nephroma was confirmed at operation to have a tumor that was too infiltrative and too advanced for primary excision. The abdomen was closed after multiple biopsies. Vincristine (1.1 mg/m2) was given intravenously once a week for a total of eight doses. Repeat CT scan confirmed shrinkage of the tumor and a nephrectomy could be performed safely and the tumor removed at the second laparotomy. CT scan repeated 1 year later showed no recurrence. This case illustrates the effective use of a single drug pre-excision chemotherapy which allowed a nephrectomy for extensive stage III mesoblastic nephroma to be carried out safely.

Accuracy of current imaging modalities in the diagnosis of synchronous bilateral Wilms' tumor. A report from the National Wilms Tumor Study Group

BACKGROUND

Five percent of patients with Wilms' tumor will present with bilateral disease. Recent reports suggest that preoperative imaging studies can exclude contralateral disease reliably, obviating the need for formal surgical exploration of the contralateral kidney. This study was undertaken to determine the accuracy of preoperative imaging in diagnosing bilateral Wilms' tumor.

METHODS

The charts of 122 patients with synchronous bilateral Wilms' tumor enrolled in National Wilms Tumor Study-4 were reviewed. With the exception of one child, all had an abdominal computed tomography (CT), ultrasound, or magnetic resonance imaging performed.

RESULTS

There were nine patients (7%) in whom the diagnosis of bilaterality was missed by the preoperative imaging studies. All but one of the missed lesions were small, five less than 1 cm and three 1-3 cm. The accuracy of each imaging modality was correlated with tumor size. Computed tomography was more sensitive in detecting bilaterality than ultrasound. However, there was not a single study that was able to detect more than 50% of lesions less than 1 cm in greatest dimension.

CONCLUSIONS

This review indicates that even with current advances in imaging technology, synchronous bilateral Wilms' tumor will go unrecognized in 7% of patients if formal exploration of the contralateral kidney is omitted. Although this represents a small percentage of all patients presenting with Wilms' tumor, preoperative diagnosis of bilaterality is essential if parenchymal-sparing procedures are to be performed. Until a more reliable indicator of bilateral disease is found, exploration of the contralateral kidney continues to be recommended.

Current management of Wilms' tumor

Most children with Wilms' tumor can now expect remarkably good survival. Current protocols have placed greater emphasis on reducing the morbidity of treatment for low-risk patients reserving intensive treatment for selected high-risk patients. This review addresses recent advances and current recommendations for the treatment of nephroblastoma. Controversial issues regarding the surgical management of these children are also discussed.