Wilms’ tumor management

The clinical impact of observer variability in lung nodule classification in children with Wilms tumour

OBJECTIVES

To investigate the extent to which observer variability of computed tomography (CT) lung nodule assessment may affect clinical treatment stratification in Wilms tumour (WT) patients, according to the recent Société Internationale d'Oncologie Pédiatrique Renal Tumour Study Group (SIOP-RTSG) UMBRELLA protocol.

METHODS

I: CT thoraces of children with WT submitted for central review were used to estimate size distribution of lung metastases. II: Scans were selected for blinded review by five radiologists to determine intra- and inter-observer variability. They assessed identical scans on two occasions 6 months apart. III: Monte Carlo simulation (MCMC) was used to predict the clinical impact of observer variation when applying the UMBRELLA protocol size criteria.

RESULTS

Lung nodules were found in 84 out of 360 (23%) children with WT. For 21 identified lung nodules, inter-observer limits of agreement (LOA) for the five readers were ±2.4 and ±1.4 mm (AP diameter), ±1.9 and ±1.8 mm (TS diameter) and ±2.0 and ±2.4 mm (LS diameter) at assessments 1 and 2. Intra-observer LOA across the three dimensions were ±1.5, ±2.2, ±3.5, ±3.1 and ±2.6 mm (readers 1-5). MCMC demonstrated that 17% of the patients with a 'true' nodule size of ≥3 mm will be scored as <3 mm, and 21% of the patients with a 'true' nodule size of <3 mm will be scored as being ≥3 mm.

CONCLUSION

A significant intra-inter observer variation was found when measuring lung nodules on CT for patients with WT. This may have significant implications on treatment stratification, and thereby outcome, when applying a threshold of ≥3 mm for a lung nodule to dictate metastatic status.

A 10-year study of the outcome of wilms' tumor in central India and identifying practice gaps

Introduction:

Despite remarkable improvement in Wilms' tumor (WT) survival in Western world, sub-optimal outcome in resource-constrained settings is influenced by late presentation, larger size, and poor access to treatment. This prompted us to study the outcome at a tertiary care center and to identify the global and local practice gaps.

Materials and Methods:

A retrospective, observational study of WT was conducted from October 2009 to September 2019 at a tertiary care setting. Following the National Wilms' Tumor Study Group protocol, an upfront nephrectomy (unilateral resectable tumors) and preoperative chemotherapy (large/unresectable Stage I–III) were followed. The records were reviewed for demographics, stage, preoperative chemotherapy, predictive factors, and outcome. Survival curves were plotted by the Kaplan–Meier method, and analysis was performed using the SPSS software version 16.

Results:

One hundred and fifty-six children were included, median age was 4.1 years, with a male predominance. The most common stages of the presentation were II (40.4%) and III (34.6%). An upfront surgery was done in 27.6%, while remaining received preoperative chemotherapy. The median follow-up was 22 months, and the events included relapse in 46 (29.48%) and death in 54 (34.61%). The mean survival time was 45.7 (95% confidence interval [CI], 41.08–50.30). The 2-year overall survival was 65.38% (95% CI, 59–73), and the 2-year event-free survival was 36% (95% CI, 32–41). On comparison of the impact of preoperative chemotherapy, the survival estimates in Stages I–III and relapse rate were statistically similar, tumor size reduced significantly, and tumor spill was significantly lower (P < 0.05).

Conclusion:

WT is associated with late presentation, sub-optimal survival, and higher relapse in our setting associated with practice gaps related to the management including practice violations.

Results of Treatment for Patients With Multicentric or Bilaterally Predisposed Unilateral Wilms Tumor (AREN0534): A report from the Children's Oncology Group

BACKGROUND

A primary objective of Children's Oncology Group study AREN0534 (Treatment for Patients With Multicentric or Bilaterally Predisposed, Unilateral Wilms Tumor) was to facilitate partial nephrectomy in 25% of children with bilaterally predisposed unilateral tumors (Wilms tumor/aniridia/genitourinary anomalies/range of developmental delays [WAGR] syndrome; and multifocal and overgrowth syndromes). The purpose of this prospective study was to achieve excellent event-free survival (EFS) and overall survival (OS) while preserving renal tissue through preoperative chemotherapy, completing definitive surgery by 12 weeks from diagnosis, and modifying postoperative chemotherapy based on histologic response.

METHODS

The treating institution identified whether a predisposition syndrome existed. Patients underwent a central review of imaging studies through the biology and classification study AREN03B2 and then were eligible to enroll on AREN0534. Patients were treated with induction chemotherapy determined by localized or metastatic disease on imaging (and histology if a biopsy had been undertaken). Surgery was based on radiographic response at 6 or 12 weeks. Further chemotherapy was determined by histology. Patients who had stage III or IV disease with favorable histology received radiotherapy as well as those who had stage I through IV anaplasia.

RESULTS

In total, 34 patients were evaluable, including 13 males and 21 females with a mean age at diagnosis of 2.79 years (range, 0.49-8.78 years). The median follow-up was 4.49 years (range, 1.67-8.01 years). The underlying diagnosis included Beckwith-Wiedemann syndrome in 9 patients, hemihypertrophy in 9 patients, multicentric tumors in 10 patients, WAGR syndrome in 2 patients, a solitary kidney in 2 patients, Denys-Drash syndrome in 1 patient, and Simpson-Golabi-Behmel syndrome in 1 patient. The 4-year EFS and OS rates were 94% (95% CI, 85.2%-100%) and 100%, respectively. Two patients relapsed (1 tumor bed, 1 abdomen), and none had disease progression during induction. According to Response Evaluation Criteria in Solid Tumor 1.1 criteria, radiographic responses included a complete response in 2 patients, a partial response in 21 patients, stable disease in 11 patients, and progressive disease in 0 patients. Posttherapy histologic classification was low-risk in 13 patients (including the 2 complete responders), intermediate-risk in 15 patients, and high-risk in 6 patients (1 focal anaplasia and 5 blastemal subtype). Prenephrectomy chemotherapy facilitated renal preservation in 22 of 34 patients (65%).

CONCLUSIONS

A standardized approach of preoperative chemotherapy, surgical resection within 12 weeks, and histology-based postoperative chemotherapy results in excellent EFS, OS, and preservation of renal parenchyma.

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.

Nephrectomy in children with wilms' tumor: 15 years of experience with "Tumor Delivery Technique"

BACKGROUND

The contemporary surgical approach to Wilms' tumors follows that used in adults with renal cell carcinomas, namely, early occlusion of the renal vessels and then removal of the kidney as an intact mass. For years, the surgical approach at our institution has been different, starting with blunt separation of the kidney from the surrounding tissues, followed by its delivery outside the abdominal cavity while it is only attached to the major blood vessels which are subsequently ligated. We aimed to present this "tumor delivery technique" and evaluate its outcomes.

MATERIALS AND METHODS

We retrospectively reviewed medical records of children who underwent nephrectomy for Wilms' tumor using "tumor delivery technique." All procedures were performed by the same team, according to the same surgical principles.

RESULTS

Between 2000 and 2015, 36 children were operated. Median age was 31 months (interquartile range [IQR]: 6-45 mo), and median maximal tumor diameter was 10 cm (IQR: 8-13.9 cm). Tumors were located to the right side in 47%, left side in 42%, and bilateral in 11%. Twelve children have received preoperative neoadjuvant chemotherapy. Capsular disruption and tumor spillage were documented in 4 cases (11%).

CONCLUSIONS

"Tumor delivery technique" is an easy and safe approach which might reduce the overall complication rates and the incidence of intraoperative tumor spillage.

HMGA2 overexpression predicts relapse susceptibility of blastemal Wilms tumor patients

Wilms tumor (WT) is an embryonal malignant neoplasm of the kidney that accounts for 6-7% of all childhood cancers. WT seems to derive from multipotent embryonic renal stem cells that have failed to differentiate properly. Since mechanisms underlying WT tumorigenesis remain largely unknown, the aim of this study was to explore the expression of embryonic stem cell (ESC) markers in samples of WT patients after chemotherapy treatment SIOP protocol, as the gene expression patterns of ESC are like those of most cancer cells. We found that expression of ESC markers is heterogeneous, and depends on histological WT components. Interestingly, among ESC markers, HMGA2 was expressed significantly stronger in the blastemal component than in the stromal and the normal kidney. Moreover, two subsets of patients of WT blastemal type were identified, depending on the expression levels of HMGA2. High HMGA2 expression levels were significantly associated with a higher proliferation rate (p=0.0345) and worse patient prognosis (p=0.0289). The expression of HMGA2 was a stage-independent factor of clinical outcome in blastemal WT patients. Our multivariate analyses demonstrated the association between LIN28B-LET7A-HMGA2 expression, and the positive correlation between HMGA2 and SLUG expression (p=0.0358) in blastemal WT components. In addition, patients with a poor prognosis and high HMGA2 expression presented high levels of MDR3 (multidrug resistance transporter). Our findings suggest that HMGA2 plays a prominent role in the pathogenesis of a subset of blastemal WT, strongly associated with relapse and resistance to chemotherapy.

Multidrug resistance transporter profile reveals MDR3 as a marker for stratification of blastemal Wilms tumour patients

Wilms tumour (WT) is the most common renal tumour in children. Most WT patients respond to chemotherapy, but subsets of tumours develop resistance to chemotherapeutic agents, which is a major obstacle in their successful treatment. Multidrug resistance transporters play a crucial role in the development of resistance in cancer due to the efflux of anticancer agents out of cells. The aim of this study was to explore several human multidrug resistance transporters in 46 WT and 40 non-neoplastic control tissues (normal kidney) from patients selected after chemotherapy treatment SIOP 93–01, SIOP 2001. Our data showed that the majority of the studied multidrug resistance transporters were downregulated or unchanged between tumours and control tissues. However, BCRP1, MDR3 and MRP1 were upregulated in tumours versus control tissues. MDR3 and MRP1 overexpression correlated with high-risk tumours (SIOP classification) (p = 0.0022 and p < 0.0001, respectively) and the time of disease-free survival was significantly shorter in patients with high transcript levels of MDR3 (p = 0.0359). MDR3 and MRP1 play a role in drug resistance in WT treatment, probably by alteration of an unspecific drug excretion system. Besides, within the blastemal subtype, we observed patients with low MDR3 expression were significantly associated with a better outcome than patients with high MDR3 expression. We could define two types of blastemal WT associated with different disease outcomes, enabling the stratification of blastemal WT patients based on the expression levels of the multidrug resistance transporter MDR3.

Malignant renal tumors in childhood: report of 54 cases treated at a single institution

BACKGROUND

Wilms tumor is the most common primary renal malignancy occurring in childhood. Significant improvement has been made in the treatment of children with Wilms tumor. However, the treatment of patients with non-Wilms renal tumors remains challenging.

METHODS

Between 1991 and 2010, 70 children with renal tumors were diagnosed at a single institution. Fifty-four patients were histologically confirmed and divided into three groups, including 42 Wilms tumors, seven clear cell sarcomas of kidney, and five malignant rhabdoid tumors. Most patients underwent unilateral nephrectomy and lymph node sampling followed by adjuvant chemotherapy. Twenty-one of these patients subsequently received radiotherapy.

RESULTS

During follow-up, 12 patients died of progressive disease and one died of operative mortality. One patient with unilateral pleural metastases subsequently underwent hematopoietic stem cell transplantation. The median survival time of all patients was 88 months. Children under 2 years of age at diagnosis with Wilms tumor or clear cell sarcoma of kidney had an excellent survival rate of 100% compared to the 0% survival rate of MRT.

CONCLUSION

Younger age at diagnosis bore a better prognosis than did older age, whereas a diagnosis of malignant rhabdoid tumor portended a worse prognosis. Younger patients and appropriate treatment may have contributed to the improved prognosis of clear cell sarcoma of kidney.

Wilms' tumor: biology, diagnosis and treatment

Wilms' tumor is the commonest renal tumor of childhood affecting one in 10,000 children. It is also one of the successes of paediatric oncology with long term survival above 90% for localised disease and 75% for metastatic disease. Successful management of Wilms' tumor necessitates meticulous attention to correct staging of the tumor and a collaborative effort between paediatric oncologists, specialist surgeons, radiologists, pathologists, and radiation oncologists. Although current treatment protocols are based on risk assignment to minimise toxicity for low risk patients and improve outcomes for those with high risk disease, challenges remain in identifying novel molecular, histological and clinical risk factors for stratification of treatment intensity. Knowledge about Wilms' tumor biology and treatment is evolving rapidly and remains a paradigm for multimodal malignancy treatment. Future efforts will focus on the use of biomarkers to improve risk stratification and the introduction of newer molecularly targeted therapies that will minimise toxicity and improve the outcomes for patients with unfavourable histology and recurrent disease. The aim of this article is to summarise advances in our understanding of the biology of Wilms' tumor and to describe the current approaches to clinical management of patients.

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.

Nodal evaluation in Wilms' tumors: analysis of the national cancer data base

OBJECTIVE

We used a large US clinical cancer registry to assess nodal evaluation performance in children with Wilms' Tumors (WT), to determined factors associated with nodal evaluation, and to define the prognostic importance of nodal status.

SUMMARY BACKGROUND DATA

Lymph node assessment remains a part of accurate staging and helps determine therapy for patients with WT. Lack of nodal assessment has been noted but not well studied.

METHODS

Patients (0-18 years) with WT from the National Cancer Data Base (1985-2001) were assessed for nodal evaluation. Logistic regression was used to identify factors associated with the likelihood of lymph node evaluation. Survival was estimated using the Kaplan-Meier method. Cox regression was used to estimate the risk of mortality.

RESULTS

Of 3593 patients, 1510 (42%) had no lymph nodes evaluated by pathology and reported to the National Cancer Data Base. Of 2083 patients who had lymph nodes assessed, 535 (25.7%) had positive nodes. Patients age 2 years or younger, with larger tumor size, and treated at a higher volume center were more likely to have nodes assessed (P < 0.01). Patients who had nodes evaluated had a better 5-year survival compared with those who did not have nodes evaluated (92.2% vs. 88.1%, P < 0.001). In Cox regression, nodal metastases (P < 0.001; HR: 2.2, CI: 1.6-3.0) were associated with increased risk of death after adjusting for patient, tumor, and hospital characteristics.

CONCLUSIONS

Many patients do not have lymph nodes evaluated during WT resection. Opportunities exist for improved staging and possibly survival in patients with WT through better nodal assessment.

Role of prognostic factors in the management of pediatric solid tumors

The importance of prognostic factors in predicting outcome in pediatric oncology is largely recognized, and most current protocols tailor treatment based on risk stratification. Further refinements of classical staging systems are ongoing, and the future of pediatric oncology is in the development of strategies based on individual tumor characteristics. This review details significant advances in our understanding of prognostic factors in the most common pediatric solid tumors and potential applications for clinical management.

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

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

The use of preoperative chemotherapy in Wilms' tumor with contained retroperitoneal rupture

PURPOSE

The National Wilms Tumor Study currently describes 3 indications for the use of preoperative chemotherapy: extensive caval involvement, bilateral tumors, and patients who only have a single kidney. However, the management of patients who present with a contained retroperitoneal rupture is not specifically addressed. This is relevant because of the strong possibility of peritoneal contamination when performing a primary resection and the resultant requirement for total abdominal radiation. The use of neoadjuvant chemotherapy in this subgroup of patients may be warranted.

METHODS

We retrospectively reviewed our experience with Wilms' tumor and identified 3 cases with contained rupture at presentation. Details of their initial evaluation and therapy, resection and pathologic findings, and follow-up constitute this report. Institutional review board waiver was obtained for the purposes of this review.

RESULTS

Two male patients, aged 2.9 years, and 1 female patient, aged 9.3 years, were identified. All patients received preoperative chemotherapy with vincristine and dactinomycin (n = 1) plus doxorubicin (n = 2) for 4 to 6 weeks before surgical resection. One patient underwent pretreatment computed tomography-guided biopsy of the kidney mass for diagnostic purposes. Presurgical computed tomographic scans showed resolution of perinephric blood and fluid with tumor shrinkage. Histopathologic analyses showed all tumors were resected with negative margins, and there was no intraoperative tumor spillage. All patients received 1050 to 1080 cGy of flank radiation postoperatively. All patients are currently alive at follow-up without evidence of local recurrence or distant disease.

CONCLUSIONS

Neoadjuvant chemotherapy allowed for complete resection and avoidance of total abdominal radiation in 3 patients with ruptured Wilms' tumor and hematoma within the retroperitoneum. These data support the use of initial chemotherapy in children with retroperitoneal rupture and hematoma of Wilms' tumor at diagnosis.

Progression of localised Wilms’ tumour during preoperative chemotherapy is an independent prognostic factor: A report from the SIOP 93–01 nephroblastoma trial and study

The SIOP nephroblastoma clinical trials have previously demonstrated that preoperative chemotherapy is advantageous for patients with nephroblastoma (Wilms' tumour). However, some primary tumours increase in size during preoperative chemotherapy, and to investigate the clinical relevance of this progression we studied the patient cohort with increasing tumours included in the SIOP 93-01 study (June 1993 to June 2000). Patients were considered eligible if they had a confirmed localised Wilms' tumour that had been measured in at least two dimensions at diagnosis and before surgery. Tumour response to preoperative chemotherapy was defined according to criteria set by the World Health Organisation (WHO). Patient characteristics in the different response groups were compared and related to event-free survival and overall survival. Patient records were studied regarding compliance with protocol. Tumour progression during preoperative chemotherapy was observed in 57 of 1090 patients (5%) with localised Wilms' tumours. In those cases, the tumours were significantly smaller at diagnosis and were more often stage III (p=0.05) and associated with high risk histopathology (p=0.03). After adjustment for stage and risk group, progression was proved to be correlated with poorer event-free and overall survival (hazard ratio 1.9, p=0.026 and 3.2, p=0.002 respectively). In summary, progression of localised Wilms' tumours is rarely seen in patients during preoperative chemotherapy. However, independent of stage distribution and histopathological risk group, those whose tumours do increase in size have poorer event-free and overall survival.