Treatment of Relapsed Wilms’ Tumor With High-Dose Therapy and Autologous Hematopoietic Stem-Cell Rescue: The Experience at Children’s Memorial Hospital

Current status of producing autologous hematopoietic stem cells

Hematopoietic stem cells (HSCs) transplantation is an established therapy for many diseases of the hematopoietic system, for example aplastic anemia, acute myeloid leukemia and acute lymphoblastic leukemia. With the development of the HSCs research, HSCs provide an attractive method for treating hereditary blood disorders and immunotherapy of cancer by introducing gene modification. Compared with allogenic HSCs transplantation, using autologous HSCs or HSCs from induced pluripotent stem cells (iPSCs) would eliminate the probability of alloimmunization and transfusion-transmitted infectious diseases. The methods for obtaining autologous HSCs include amplifying patients' HSCs or inducing patients' somatic cells to HSCs (graph abstract). However, the biggest problem is inducing HSCs to proliferate in vitro and maintaining their stemness at the same time. Although many tests have been made to transform iPSCs to HSCs, the artificially generated HSCs still have substantial disparity compared with physiological HSCs. This review summarized the application status and obstacles to implantation of autologous HSCs and iPSC-derived HSCs. Meanwhile, we summarized the latest research progress in HSCs amplification and iPSCs reprogramming methods, which will help to solve the problems mentioned above.

High-dose chemotherapy followed by autologous stem cell rescue in Wilms tumors: French report on toxicity and efficacy

BACKGROUND

Heterogeneous data have been reported on high-dose chemotherapy (HDCT) with autologous stem cell rescue (ASCR) in Wilms tumors (WTs). We aimed to define its safety and efficacy in the French cohort, and to compare this management to current international recommendations.

METHODS

Data prospectively collected from children, adolescents, and young adults with WT treated with HDCT/ASCR between 2000 and 2016 in French centers were retrospectively analyzed. Toxicity was reported according to CTCAE v4.03.

RESULTS

Fifty-four patients received HDCT/ASCR (first line, n = 13; recurrence, n = 41). Their median age at the time of ASCR was 5.3 years (range 2.2-21.6). Main nonhematological acute grades 3-4 toxicities were digestive and renal. No significant difference of toxicity rate was observed among HDCT regimens and schedules. Two patients died shortly after ASCR (renal and multiorgan failure), and one heavily pretreated patient died of late respiratory failure. The selection criteria applied to define those patients eligible for HDCT/ASCR retrospectively matched to those currently used in the International Society of Pediatric Oncology (SIOP) UMBRELLA protocol for 38 patients, with encouraging survival rates compared to published data. The objective response rate to HDCT was 21%, with a disease control rate after HDCT of 85%. After a median follow-up of 7 years, the 5-year event-free survival (EFS) and overall survival (OS) were 54% (95% CI: 32%-76%) and 62% (95% CI: 31%-82%) for frontline patients, and 57% (95% CI: 39%-71%) and 69% (95% CI: 52%-81%) at recurrence.

CONCLUSION

HDCT was feasible and showed encouraging results in well-defined settings. Data from the current prospective protocol will help to better evaluate HDCT impact on survival.

Irinotecan Plus Doxorubicin Hydrochloride Liposomes for Relapsed or Refractory Wilms Tumor

Purpose

The prognosis of relapsed or refractory pediatric Wilms tumor (WT) is dismal, and new salvage therapies are needed. This study aimed to evaluate the efficacy of the combination of irinotecan and a doxorubicin hydrochloride liposome regimen for relapsed or refractory pediatric WT.

Patients and Methods

The present study enrolled relapsed or refractory pediatric WT patients who were treated with the AI regimen (doxorubicin hydrochloride liposomes 40 mg/m² per day, day 1, and irinotecan 50 mg/m² per day with 90-min infusion, days 1–5; this regimen was repeated every 3 weeks) at Sun Yat-sen University Cancer Center from July 2018 to September 2020. The response was defined as the best-observed response after at least two cycles according to the Response Evaluation Criteria of Solid Tumors (RECIST 1.1), and toxicity was evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE 4.03).

Results

A total of 16 patients (male:female, 8:8) with a median age of 4.2 years (0.5–11 years) with relapsed or refractory disease were enrolled in this study, including 14 patients with relapsed disease and two patients with refractory disease. These patients received 1–8 courses (median, 3 courses) of the AI regimen. Fourteen patients were assessable for response: two with complete response (CR), five with partial response (PR), two with stable disease (SD), and five with progressive disease (PD). The objective response rate was 50% (two CR, five PR), and the disease control rate was 64% (two CR, five PR, and two SD). Seven out of 14 patients (50%) were alive at the last follow-up, ranging from 2.6 to 32.4 months. The median progression-free survival and median overall survival were 3.5 months (range 0.5–12 months) and 8 months (range 1–28 months), respectively. Sixteen patients were assessable for toxicity, with the most common grade 3 or 4 adverse events being alopecia (62%), leukopenia (40%), abdominal pain (38%), diarrhea (23%), and mucositis (16%), etc. No fatal adverse events have been observed, and modest adverse effects can be administered.

Conclusion

Irinotecan and doxorubicin hydrochloride liposome regimens have positive efficacy on relapsed or refractory pediatric WT with well-tolerated toxicity. A prospective clinical trial is warranted.

Relapsed Wilms' tumor in pediatric patients: challenges in low- to middle-income countries-a single-center experience

BACKGROUND

Wilms' tumor (WT) affects one in 10,000 children and accounts for 5% of all childhood cancers. Although the overall relapse rate for children with WT has decreased to less than 15 %, the overall survival for patients with recurrent disease remains poor at approximately 50 %. The aim of the study to evaluate the outcome of relapsed Wilms' tumor pediatric patients treated at the National Cancer Institute (NCI), Egypt, between January 2008 and December 2015.

RESULTS

One hundred thirty (130) patients diagnosed with WT during the study period, thirty (23%) patients had relapsed. The median follow up period was 22.3 months (range 3.6-140 months). The Overall Survival (OS) was 30.9% while the event-free survival (EFS) was 29.8% at a 5-year follow up period. Median time from diagnosis to relapse was 14.4 months. A second complete remission was attained in 18/30 patients (60%). The outcome of the 30 patients; 11 are alive and 19 had died. Three factors in our univariate analysis were prognostically significant for survival after relapse. The first was radiotherapy given after relapse (p = 0.012). The 5-year EFS and OS for the group that received radiotherapy were 41.9% versus 16.7% and 11.1% respectively for those that did not. The second was the state of lymph nodes among patients with local stage III (p = 0.004). Lastly, when risk stratification has been applied retrospectively on our study group, it proved to be statistically significant (p = 0.029).

CONCLUSION

Among relapsed pediatric WT, radiotherapy improved survival at the time of relapse and local stage III with positive lymph nodes had the worst survival among other stage III patients.

Autologous Stem Cell Transplantation for Children With Renal Tumors, and Adults With Wilms Tumor: Retrospective Analysis of the Japanese Transplant Registry Unified Management Program

BACKGROUND

Almost all pediatric patients with renal tumors are diagnosed with nephroblastoma (Wilms tumor), clear cell sarcoma, or malignant rhabdoid tumor. The choice of treatment is important for relapsed and refractory patients with nephroblastoma. Furthermore, clear cell sarcoma of the kidney (CCSK) and malignant rhabdoid tumor of the kidney (MRTK) have a poor prognosis compared with nephroblastoma. Thus, stem cell transplantation (SCT) is sometimes selected to treat these tumors.

PATIENTS AND METHODS

The authors targeted a total of 84 patients with nephroblastoma, CCSK, and MRTK who underwent a first autologous SCT between 1992 and 2014, and were registered in the Japanese Transplant Registry Unified Management Program system. The authors retrospectively analyzed the SCT data for survival rate.

RESULTS

Five-year overall survival rates for nephroblastoma, CCSK, and MRTK were 72.4%±6.3%, 46.8%±13.8%, and 36.4%±14.5%, respectively. The event-free survival rates at 5 years were 64.9%±6.7%, 35.7%±12.8%, and 27.3%±13.4%, respectively. The relapse rates at 5 years were 25.3%±11.4%, 46.2%±28.4%, and 60.0%±43.1%, respectively.

CONCLUSION

Although the survival rate for nephroblastoma was relatively high, those of CCSK and MRTK were poor.

High-dose chemotherapy and autologous hematopoietic stem-cell rescue for treatment of relapsed and refractory Wilms tumor: Re-evaluating outcomes

Wilms tumor (WT) treatment regimens are curative for more than 80% of patients, but those with relapsed or refractory disease continue to have poor outcomes. High-dose chemotherapy followed by autologous stem cell rescue is often utilized although outcomes remain variable. We report on HD-ASCR outcomes in 24 patients with relapsed or refractory Wilms tumor. Three-year disease free and overall survival are 46% and 60%, respectively, which is similar to those reported for conventional salvage therapies. These outcomes suggest that conventional salvage therapies should be employed for relapsed and refractory WT rather than HD-ASCR.

Significant correlation between peripheral blood CD34+ cell count in children prior to aphaeresis and CD34+ cell yield following aphaeresis: A single-center experience

Numerous adults' studies demonstrated that preaphaeresis CD34+ cells significantly correlate with the number of CD34+ cells collected by the aphaeresis procedure. Equivalent studies in children are scarce. We studied retrospectively 92 aphaeresis procedures performed following chemotherapy (44) or in steady state (48) in 60 pediatric patients (40 males, 20 females), median age of 7.5 years. Aphaeresis procedures were performed using a SPECTRA Optica (TERUMOBCT) continuous flow cell separator. CD34+ cell concentrations were assessed using flow cytometry. A highly significant correlation between peripheral CD34 cell count on the day of aphaeresis and CD34 cell yield per kg (R²  = .824, P < .0001) was demonstrated. A higher preaphaeresis CD34 cell count was demonstrated in patients with higher preaphaeresis white blood cell count, in patients with brain tumors, and in patients who received chemotherapy as part of their mobilization protocol. A threshold number of 20 peripheral CD34+ cell/μL was found to predict harvesting of 3 × 10⁶ stem cells/kg, and 30 peripheral CD34+ cell/μL for harvesting of 5 × 10⁶ stem cells/kg. This significant correlation between peripheral CD34 cell count and CD34 cell yield, and the threshold number of peripheral CD34 found to predict adequate harvesting can be useful in planning the optimal time for aphaeresis in children.

Outcomes following autologous hematopoietic stem cell transplant for patients with relapsed Wilms' tumor: a CIBMTR retrospective analysis

Despite the marked improvement in the overall survival (OS) for patients diagnosed with Wilms' tumor (WT), the outcomes for those who experience relapse have remained disappointing. We describe the outcomes of 253 patients with relapsed WT who received high-dose chemotherapy (HDT) followed by autologous hematopoietic stem cell transplant (HCT) between 1990 and 2013, and were reported to the Center for International Blood and Marrow Transplantation Research. The 5-year estimates for event-free survival (EFS) and OS were 36% (95% confidence interval (CI); 29-43%) and 45% (95 CI; 38-51%), respectively. Relapse of primary disease was the cause of death in 81% of the population. EFS, OS, relapse and transplant-related mortality showed no significant differences when broken down by disease status at transplant, time from diagnosis to transplant, year of transplant or conditioning regimen. Our data suggest that HDT followed by autologous HCT for relapsed WT is well tolerated and outcomes are similar to those reported in the literature. As attempts to conduct a randomized trial comparing maintenance chemotherapy with consolidation versus HDT followed by stem cell transplant have failed, one should balance the potential benefits with the yet unknown long-term risks. As disease recurrence continues to be the most common cause of death, future research should focus on the development of consolidation therapies for those patients achieving complete response to therapy.

Advances in Wilms Tumor Treatment and Biology: Progress Through International Collaboration

Clinical trials in Wilms tumor (WT) have resulted in overall survival rates of greater than 90%. This achievement is especially remarkable because improvements in disease-specific survival have occurred concurrently with a reduction of therapy for large patient subgroups. However, the outcomes for certain patient subgroups, including those with unfavorable histologic and molecular features, bilateral disease, and recurrent disease, remain well below the benchmark survival rate of 90%. Therapy for WT has been advanced in part by an increasingly complex risk-stratification system based on patient age; tumor stage, histology, and volume; response to chemotherapy; and loss of heterozygosity at chromosomes 1p and 16q. A consequence of this system has been the apportionment of patients into such small subgroups that only collaboration between large international WT study groups will support clinical trials that are sufficiently powered to answer challenging questions that move the field forward. This article gives an overview of the Children's Oncology Group and International Society of Pediatric Oncology approaches to WT and focuses on four subgroups (stage IV, initially inoperable, bilateral, and relapsed WT) for which international collaboration is pressing. In addition, biologic insights resulting from collaborative laboratory research are discussed. A coordinated expansion of international collaboration in both clinical trials and laboratory science will provide real opportunity to improve the treatment and outcomes for children with renal tumors on a global level.

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.

Autologous hematopoietic stem cell transplantation for pediatric solid tumors

While advances in the treatment of pediatric cancers have increased cure rates, children with metastatic or recurrent solid tumors have a dismal prognosis despite initial transient responses to therapy. Autologous hematopoietic stem cell transplantation takes advantage of the steep dose-response relationship observed with many chemotherapeutic agents. While clearly demonstrated to improve outcomes in patients with metastatic neuroblastoma, autologous hematopoietic stem cell transplantation is also frequently used to treat patients with other high-risk diseases such as Ewing sarcoma, osteosarcoma, rhabdomyosarcoma, Wilms' tumor, retinoblastoma, germ cell tumors, lymphomas and brain tumors. Most published experience consists of retrospective, single-arm studies; randomized clinical trials are lacking, due in part to the rarity of pediatric cancers treatable by autologous hematopoietic stem cell transplantation. These published literature demonstrate that autologous hematopoietic stem cell transplantation results in most cases in equivalent or superior outcomes when compared with conventional therapies. However, patient heterogeneity, patient selection, graft characteristics and processing and the varied conditioning regimens are additional factors to consider. Since the inception of autologous hematopoietic stem cell transplantation, regimen-related toxicity has markedly decreased and the vast majority of treatment failures are now due to disease recurrence. Prospective clinical trials are needed to identify specific high-risk patient populations, with randomization (when possible) to compare outcomes of patients undergoing autologous hematopoietic stem cell transplantation with those receiving standard therapy. In addition, investigators need to better define the role of autologous hematopoietic stem cell transplantation in these solid tumors, particularly in combination with other therapeutic modalities such as immunotherapy and novel cell processing methodologies.

Consolidation treatment for high risk solid tumors in children with myeloablative chemotherapy and autologous hematopoietic progenitor stem cell transplantation

Background

In childhood cancer, consolidation treatment with chemotherapy followed by autologous hematopoietic progenitor stem cell transplantation is currently an accepted treatment modality in patients with high-risk solid tumors or in patients who have relapsed after conventional treatment.

Objectives

The objective of this study was to describe the results of transplantation of a group of children who had high-risk solid tumors or relapsed after conventional chemotherapy regimens.

Methods

A retrospective analysis was conducted from January 1998 to October 2004 of all children with pathologic diagnoses of high-risk solid tumors or children that had previously relapsed after conventional chemotherapy and that were subsequently submitted to autologous hematopoietic progenitor stem cell transplantation. The analysis included overall survival rates, event-free survival rates, mortality rates and chemotherapy complications.

Results

Nineteen patients were submitted to this approach. The age range was from 27 to 196 months with a median age of 52 months. The overall survival rate at 100 days was observed in 79%, the three-year event-free survival rate was 63%. The mortality rate secondary to the myeloablative chemotherapy regimen was 21% (n = 4). Only three patients (15.8%) relapsed with tumor progression after transplant.

Conclusion

Autologous hematopoietic progenitor stem cell transplantation is still a successful procedure in patients with solid tumors refractory to conventional chemotherapy.

The isolation and characterization of renal cancer initiating cells from human Wilms' tumour xenografts unveils new therapeutic targets

There are considerable differences in tumour biology between adult and paediatric cancers. The existence of cancer initiating cells/cancer stem cells (CIC/CSC) in paediatric solid tumours is currently unclear. Here, we show the successful propagation of primary human Wilms' tumour (WT), a common paediatric renal malignancy, in immunodeficient mice, demonstrating the presence of a population of highly proliferative CIC/CSCs capable of serial xenograft initiation. Cell sorting and limiting dilution transplantation analysis of xenograft cells identified WT CSCs that harbour a primitive undifferentiated – NCAM1 expressing – “blastema” phenotype, including a capacity to expand and differentiate into the mature renal-like cell types observed in the primary tumour. WT CSCs, which can be further enriched by aldehyde dehydrogenase activity, overexpressed renal stemness and genes linked to poor patient prognosis, showed preferential protein expression of phosphorylated PKB/Akt and strong reduction of the miR-200 family. Complete eradication of WT in multiple xenograft models was achieved with a human NCAM antibody drug conjugate. The existence of CIC/CSCs in WT provides new therapeutic targets.

An international strategy to determine the role of high dose therapy in recurrent Wilms' tumour

PURPOSE

To review event-free (EFS) and overall survival (OS) from publications describing outcome for children with relapsed Wilms' tumour. Comparisons are made between those receiving myeloablative high dose chemotherapy with autologous stem-cell rescue (HDT) and those not (NoHDT).

MATERIALS AND METHODS

Relevant information was extracted from individual patient or summary data and 3-year EFS and OS rates established. These rates were combined in a weighted manner to derive hazard ratios (HRs).

RESULTS

Nineteen publications were identified (5 HDT, 6 NoHDT, 8 both). Pooling all studies suggested an advantage to HDT with a hazard ratio (HR) for EFS of 0.87 (95% confidence interval (CI) 0.67-1.12) and 0.94 (0.71-1.24) for OS. A stratified analysis confined to studies that provided individual patient data on both HDT and NoHDT gave HRs of 0.83 (0.56-1.24) and 0.92 (0.59-1.41). Further, analyses of risk groups, defined by treatment and/or histology prior to first relapse, suggested a HR for EFS of 0.90 (95% CI 0.62-1.31) for those of high and 0.50 (CI 0.31-0.82) for the very high risk patients.

CONCLUSION

The evidence suggests, although there are many caveats since the information summarised here is not from randomised trials, a great deal of uncertainty concerning the role of HDT in patients following relapse after treatment for their Wilms' tumour. For each risk group we propose a randomised trial comparing a standard with a more intensive therapy with specific choice of regimen tailored to the risk group (and co-operative groups) concerned. A synthesis of updated evidence from studies in this overview together with any emerging studies and future trial information will form the basis for future evidence-based clinical decision-making.

Renal function after tandem high-dose chemotherapy and autologous stem cell transplantation in children with Wilms tumor

Despite increasing evidence that tandem HDCT and autoSCT might improve the survival of patients with high-risk solid tumors, patients with Wilms tumor may be at high risk of acute and chronic renal impairment during and after tandem HDCT/autoSCT because they usually have a single kidney. We investigated the feasibility of tandem HDCT/autoSCT in patients with Wilms tumor, focusing on renal function. Six patients with relapsed/progressed Wilms tumor were assigned to undergo tandem HDCT/autoSCT. One patient developed transient ARF during the first HDCT/autoSCT. All other patients underwent the second HDCT/autoSCT as scheduled. Acute renal dysfunction during the second HDCT/autoSCT was transient and manageable. Indicators of glomerular function such as creatinine clearance, serum creatinine, and albumin excretion were in the normal range at three yr after tandem HDCT/autoSCT. Subclinical tubular dysfunctions, such as increased excretion of β-N-acetylglucosaminidase and β2-microglobulin, were identified at one and three yr after tandem HDCT/autoSCT; however, no patient required treatment for these conditions. These results are helpful to consider tandem HDCT/autoSCT as a treatment option in patients with Wilms tumor. Longer duration of follow-up and close monitoring of tubular function are required if tandem HDCT/autoSCT is indicated in patients with Wilms tumor.

Wilms' tumor: An update

Wilms' tumor (WT) is the commonest pediatric renal tumor, predominantly seen in children less than five years of age. The majority of patients present with an abdominal lump and CT scan is the usual imaging modality for determining the extent of disease. With multimodality management, the results of treatment of WT have improved dramatically over the last 50 years. The treatment protocols have been devised and modified repeatedly depending on evidence from randomized trials by several cooperative groups - mainly National Wilms' Tumor Study Group (NWTSG) and the International Society of Pediatric Oncology (SIOP). The NWTSG recommends primary surgery followed by chemotherapy while SIOP advocates four weeks of chemotherapy prior to surgery. The regimen, dose and duration of chemotherapy have been repeatedly modified to reduce toxicity while maintaining efficacy. The role of radiation therapy has also been customized. Most centers have reported excellent survival rates with the modern day treatment protocols, except in patients with an unfavorable histology. The results of treatment of relapsed WT have also improved with newer drugs and combinations being used for the same.

Double high-dose chemotherapy and stem cell transplantation in adult Wilms’ tumor

High-dose chemotherapy intensification and hematopoietic stem cell support remains a valuable treatment option for the rare patient with relapsed Wilms’ tumor. We report a 22-year-old adult male with an initially diagnosed stage II Wilms’ tumor, treated by nephrectomy followed by adjuvant chemotherapy. After 1 year, an intra-abdominal relapse was treated with salvage ifosfamide carboplatin etoposide chemotherapy followed by autologous hematopoietic stem cell mobilization. It was intended that he would receive two tandem cycles of high-dose chemotherapy; the first consisting of melphalan etoposide carboplatin; however, the patient did not return to receive the second cycle while in remission, but did return later with grossly relapsed disease. He was then treated with a novel preparative regimen incorporating high-dose topotecan (topotecan, melphalan and cyclophosphamide). This case confirms the feasibility of double high-dose chemotherapy with hematopoietic stem cell support in relapsed Wilms’ tumor. A detailed discussion with an extensive review of the literature, regarding studies evaluating the role and indications of high-dose chemotherapy in Wilms’ tumor is provided.

Matched unrelated umbilical cord blood transplantation for a patient with chemotherapy resistant Wilms tumor

We report a patient with chemotherapy refractory Wilms tumor who underwent an unrelated donor cord blood transplant for chemotherapy refractory disease. The preparative regimen consisted of busulfan, melphalan, and anti-thymocyte globulin, and was well tolerated. This patient did not experience significant toxicity related to the chemotherapy regimen and did not develop any graft versus host disease from his HLA (A, B, DR) 6/6 matched cord blood transplant. Follow-up CT scans 2 years post-transplant have shown no evidence of disease progression, with only a few pulmonary nodules remaining, which are unchanged in size from his pre-transplant CT scan. It is possible that high-dose chemotherapy and stem cell transplantation can be curative in patients with tumors that are non-responsive to conventional chemotherapy.

Efficacy of high-dose chemotherapy and autologous stem cell transplant for recurrent Wilms' tumor: a meta-analysis

Long-term survival of relapsed Wilms' tumor patients is about 40% to 70%. Modern second-line treatment consists of either (a) salvage chemotherapy+/-radiation therapy (CT) or (b) chemotherapy followed by high-dose chemotherapy and autologous hematopoietic stem cell rescue (ASCR). Here, we conduct an individual patient data meta-analysis on 100 patients collected from 6 studies to determine characteristics that predict survival in relapsed patients who received ASCR therapy. We compare these results with survival data on 118 CT treated patients from 2 recently published studies. Four year overall survival among the combined ASCR treated patients was 54.1% (95% CI: 42.8-64.1%). The ASCR patients who only relapsed in the lungs had higher 4-years survival rates 77.7% (58.6% to 88.8%) than those who relapsed in other locations and/or suffered multiple relapses 41.6% (24.8% to 57.6%). Although lung-only relapse is considered a favorable prognostic factor, there was no clear advantage for the patients treated with salvage chemotherapy. Four-year survival rates among stage I-II patients were about 30% higher with CT than ASCR, but the 2 were comparable for stage III-IV patients. These findings suggest salvage chemotherapy is typically the better choice for relapsed Wilms' tumor patients, ASCR could be considered for stage III-IV patients with a lung-only relapse.

Successful treatment of late, recurrent wilms tumor with high-dose chemotherapy and autologous stem cell rescue in third complete response

Wilms tumor relapses are infrequent, occurring in approximately 15% of favorable histology patients. Very few cases of late recurrent relapse exist in the literature. Long-term survival after autologous stem cell rescue ranges from 40% to 73%, but there are very few reports of patients transplanted in their third complete response. We report a late recurrent relapse of Wilms tumor successfully treated with high-dose chemotherapy and autologous stem cell rescue in his third complete response who remains disease free 15 months posttransplant.

Treatment of relapsed Wilms tumors: lessons learned

Treatment regimens for recurrent Wilms tumor (WT) are currently designed to include drugs that are not used during primary chemotherapy, using a risk-stratified approach. Therapy of recurrent disease depends on the nature of initial treatment, and of recognized prognostic indicators inherent in the primary tumor. Several highly effective chemotherapy regimens, including ifosfamide-carboplatin-etoposide, cyclophosphamide-etoposide and carboplatin-etoposide, are considered first treatment choice for recurrent disease. While intense-dose chemotherapy is uniformly accepted to treat high-risk recurrent WTs, the optimal therapy for standard-risk children has yet to be defined, owing to the small number of such patients and their relatively better prognosis compared with high-risk recurrences. Recurrent tumors among those defined as very-high risk are likely to develop chemoresistant disease, and novel therapeutic strategies will be necessary to cure these patients. Evidence on how to properly administer surgery and radiotherapy at relapse is more fragmentary. The authors have reviewed the available experiences concerning the treatment of recurrent WT, and have attempted to provide the most up-to-date recommendations regarding the optimal risk-based treatment for these patients.

Long-term survival after autologous peripheral blood stem cell transplantation in two patients with malignant rhabdoid tumor of the kidney

A 5-month-old male with stage II malignant rhabdoid tumor of the kidney (MRTK) and a 24-month-old male with stage III MRTK were treated with surgical resection of tumors and chemotherapy of alternating ICE (ifosfamide, carboplatin, and etoposide) and VDC (vincristine, doxorubicin, and cyclophosphamide), followed by high-dose chemotherapy using etoposide, carboplatin, and melphalan with autologous hematopoietic stem cell transplantation (SCT). Two patients have been alive without any evidence of disease for 30 and 37 months after diagnosis, respectively, and require no medication. Consolidation with SCT should be further studies for selected patients with high-risk MRTK.

Current and emerging chemotherapy treatment strategies for Wilms tumor in North America

Wilms tumor is the most common primary renal malignancy occurring in childhood. Approximately 500 children are diagnosed with Wilms tumor annually in the US alone, most of whom are aged <5 years. Several prognostic factors have been identified, including stage of disease, tumor histology, patient age, tumor weight, and tumor-specific loss of heterozygosity for chromosomes 1p and 16q. During the period from 1969 to 2002, the National Wilms Tumor Study Group coordinated five multicenter Wilms tumor studies. The overall survival rate for Wilms tumor has risen to >90% for patients with tumors of favorable histology. However, the treatment of patients with Wilms tumor with anaplastic histology remains challenging. The optimal treatment strategies for Wilms tumor in relapse will be studied via international collaboration in the near future. Goals of emerging studies include minimizing toxicity while maintaining the outstanding cure rates for patients with a good prognosis and, through advancing biologic understanding and developing novel therapeutic approaches, improving the prognosis for those patients in whom effective cure of their disease continues to elude physicians.

Treatment of high-risk relapsed Wilms tumor with dose-intensive chemotherapy, marrow-ablative chemotherapy, and autologous hematopoietic stem cell support: experience by the Italian Association of Pediatric Hematology and Oncology

BACKGROUND

We evaluated an intensified chemotherapy strategy in children with Wilms tumor who relapsed with high-risk features.

PROCEDURES

From January 2001 to June 2006, we treated 20 consecutive children with reinduction chemotherapy (using ifosfamide/carboplatin/etoposide in 15/20 cases), with (n = 15) or without (n = 5) subsequent high-dose chemotherapy and hematopoietic stem cell support, surgery where feasible, and radiation therapy. The median time to relapse was 10 months after nephrectomy. All but two children initially received doxorubicin as first-line therapy.

RESULTS

All patients were assessed for outcome: 13 are currently alive, 12 of them in remission a median 25 months since their relapse, one with progressing tumor. The treatment was unsuccessful in eight children: the disease progressed during reinduction in three, and relapsed in five. There was one toxic death. All transplanted patients engrafted to a neutrophil count >0.5 x 10(3)/microl after a median 11 days, and to an unsustained platelet count >25,000/microl after a median of 13 days. Three-year disease-free and overall survival rates were 56 +/- 12% and 55 +/- 13%, respectively. Neither recurrence within 12 months of nephrectomy nor extra-lung recurrence negatively affected outcome. A survival advantage was demonstrated in patients without disease evidence prior to transplant.

CONCLUSION

A disease-free survival rate nearing 50% is a realistic target in children with high-risk recurrent Wilms tumor. The benefit of autologous hematopoietic stem cell transplantation for consolidation deserves to be investigated in a randomized, controlled study.

Treatment of Wilms tumor relapsing after initial treatment with vincristine, actinomycin D, and doxorubicin. A report from the National Wilms Tumor Study Group

OBJECTIVE

We evaluated the use of alternating cycles of cyclophosphamide/etoposide and carboplatin/etoposide in children entered on National Wilms Tumor Study (NWTS)-5 who were diagnosed between August 1, 1995 and May 31, 2002 and who relapsed after chemotherapy with vincristine, actinomycin D, and doxorubicin (VAD) and radiation therapy (DD-4A).

PATIENTS AND METHODS

One hundred three patients who relapsed or had progressive disease after initial VAD chemotherapy and radiation therapy were registered on stratum C of the NWTS-5 Relapse protocol. Twelve patients were not evaluable: five due to insufficient data, six due to major protocol violations, and one for refusal of therapy. Among the 91 remaining patients, 14 with stage V Wilms tumor (WT), 1 with contralateral relapse, and 16 who did not achieve a complete response (CR) to the initial three-drug chemotherapy were not included in this analysis. Relapse treatment included alternating courses of the drug pairs cyclophosphamide/etoposide and carboplatin/etoposide, surgery, and radiation therapy.

RESULTS

The outcomes of 60 patients were analyzed. The lung was the only site of relapse for 33 patients; other sites of relapse included the operative bed, the abdomen, and liver. Four-year event-free survival (EFS) and overall survival (OS) were 42.3 and 48.0% respectively for all patients and were 48.9 and 52.8% for those who relapsed in the lungs only. Thrombocytopenia was the most frequent toxicity.

CONCLUSION

These results demonstrate that approximately one-half of children with unilateral WT who relapse after initial treatment with VAD and radiation therapy can be successfully retreated.

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.

Surgical implications for liver metastases in nephroblastoma--data from the SIOP/GPOH study

BACKGROUND

In children with Wilms' tumor, the 5-year overall survival rate is over 90% in the SIOP/GPOH study group. However, a small group of patients have tumor lesions in the liver at the time of initial diagnosis or as a recurrence. This group seems to have a worse prognosis in terms of survival. The treatment and outcome of patients with a hepatic recurrence were analyzed compared to previously published data of patients with primary hepatic metastases.

PATIENTS AND METHODS

We reviewed the records of 45 out of 1365 patients enrolled in the SIOP 93-01/GPOH study and the SIOP 2001/GPOH study between April 1, 1994 and September 30, 2004. Median age at diagnosis was 6.49 years (1.37-34.16 years) in 29 patients who were initially presented with hepatic metastases (group I) with 9 males and 20 females. In 16 children who had a recurrence of a nephroblastoma in the liver (group II), median age at diagnosis was 4.62 years (1.84-31.08 years) with 9 males and 7 females.

RESULTS

In group I out of 29 patients, 11 died at a median of 13.07 months. Overall survival in group I was 62.58%. In group II, 9 patients died at a median 52 months. Overall survival in group II was 54.7%.

CONCLUSION

This report suggests that when complicated by metastases of the liver, Wilms' tumor has a less favorable outcome. Chemotherapy and radiotherapy play a definitive role in the treatment of these children. The importance of complete resection of hepatic lesions in both groups should be emphasized.

Topotecan is active against Wilms' tumor: results of a multi-institutional phase II study

PURPOSE

A phase II study was conducted to evaluate the activity and safety of topotecan in pediatric patients with recurrent Wilms' tumor.

PATIENTS AND METHODS

Patients with favorable histology Wilms' tumor (FHWT) and recurrence after at least one salvage chemotherapy regimen or with anaplastic histology Wilms' tumor (AHWT) in first or subsequent recurrence were eligible. Patients were stratified according to histology, with statistical considerations based on the FHWT stratum. Topotecan was administered intravenously over 30 minutes for 5 days on 2 consecutive weeks. Treatment dosages were adjusted to achieve a target area under the curve (AUC) of 80 +/- 10 ng/mL*h. Tumor responses were measured after two cycles of treatment.

RESULTS

Thirty-seven patients (26 patients with FHWT) were enrolled and received a total of 94 cycles of topotecan (range, one to six cycles). The median topotecan dosage required to achieve the target AUC was 1.8 mg/m2 (range, 0.7 to 3.2 mg/m2). Of 25 assessable patients with FHWT, 12 had partial response (PR), six had stable disease (SD), and seven had progressive disease (PD), for an overall response rate of 48% (95% CI, 27.8% to 68.7%). Of 11 assessable patients with AHWT, two had PR, one had SD, and eight had PD. The main toxicities were grade 3 and 4 neutropenia (median duration, 13 days) and thrombocytopenia (median duration, 7.5 days).

CONCLUSION

Topotecan administered on a protracted schedule is active against recurrent FHWT. Inclusion of topotecan in front-line clinical trials for patients with recurrent Wilms' tumor should be considered.

Treatment of Wilms tumor relapsing after initial treatment with vincristine and actinomycin D: a report from the National Wilms Tumor Study Group

PURPOSE

NWTS-5 was a multi-institutional clinical trial for patients less than 16 years of age at diagnosis with specific renal neoplasms who were diagnosed between August 1, 1995 and May 31, 2002. A uniform approach to the treatment of patients with relapse was employed.

PATIENTS AND METHODS

Seventy-two patients who relapsed after immediate nephrectomy (stages I and II), initial chemotherapy with vincristine (VCR) and actinomycin D and no radiation therapy were registered on stratum B of the NWTS-5 relapse protocol. Four patients were not evaluable: one due to insufficient data and three due to major protocol violations. Among the 68 remaining patients, one who was 19 years of age at initial diagnosis of Wilms tumor, five with bilateral Wilms tumor at diagnosis, three who developed a contralateral relapse, and one with persistent disease were not included in this analysis. Relapse treatment included surgical excision, when feasible, radiation therapy and alternating courses of VCR, doxorubicin and cyclophosphamide and etoposide and cyclophosphamide.

RESULTS

The outcomes of 58 patients were analyzed. The lung was the only site of relapse for 31 patients. Event-free survival 4 years after relapse was 71.1% and 4-year overall survival was 81.8% for all patients and were 67.8 and 81.0% for those who relapsed only to their lungs. The most frequent toxicities were hematological.

CONCLUSIONS

These results demonstrate that a significant proportion of children with Wilms tumor who relapse after initial treatment with VCR and actinomycin D can be successfully re-treated.

Results of novel strategies for treatment of Wilms' tumor

OBJECTIVE

To evaluate treatment outcomes in Wilms' tumor (WT).

MATERIALS AND METHODS

We studied 53 children with median age of 2 years with WT, stages I-19, II-14, III-12, IV-6 and V-2. Treatment consisted of surgical excision plus adjuvant (40 children) or neoadjuvant and adjuvant chemotherapy (unresectable tumor, n=8, or caval tumor extension, n=5). Chemotherapy and radiotherapy followed protocols of Brazilian Wilms' Tumor Study Group excepting 16 cases with stage I disease that received a short duration postoperative treatment with vincristine (VCR - 11 doses) and dactinomycin (AMD - 4 doses). Relapsed WT was treated with multiagent regimens including cisplatin/carboplatin, cyclophosphamide, ifosfamide and etoposide. One patient with resistant relapsed WT was treated by high-dose conditioning chemotherapy with stem cell rescue.

RESULTS

Overall and disease-free survival rates at 5 years were respectively 88.2 +/- 5.0% and 76.7 +/- 6.6%. Short duration therapy for stage I tumor showed a disease-free survival rate of 100% in a median time of 101 months (range 14 to 248 months). Overall and disease-free survival of 10 patients with recurrent WT at 5 years was 42.8%. The child treated with high-dose chemotherapy plus stem cell transplant is alive without evidence of disease 84 months from relapse.

CONCLUSION

The postoperative chemotherapy in stage I disease can be reduced without compromising the cure rate. The treatment of unfavorable stage III and IV disease or relapsed tumor remains a challenge.

Wilms’ tumour in adults: a case report and review of the literature

BACKGROUND

Wilms' tumour is a very rare adult malignancy representing 1% of adult renal tumours. It is however the most common renal tumour of childhood, and adult patients are treated in accordance with paediatric protocols.

AIM

To review modern day management of adult Wilms' tumour.

METHODS

We report a case of adult Wilms' tumour and discuss the management including the use of newer treatment modalities.

RESULTS

Following diagnostic nephrectomy, our patient was treated with chemotherapy in accordance with North American paediatric protocols and PET scanning was used to diagnose early relapse.

CONCLUSION

In the absence of randomised controlled data, central reporting of cases of adult Wilms' Tumour may help improve management. The incorporation of newer chemotherapeutic agents, high-dose therapy and PET scanning into treatment protocols should improve outcome for these patients.

Late recurrence of Wilms' tumour with exclusive skeletal muscle phenotype 23 years after primary diagnosis

A late recurrence of Wilms' tumour (WT) 23 years after the primary diagnosis is described. The primary tumour occurred in a 10-month-old girl and showed various degrees of differentiation, including skeletal muscle phenotype. A postoperative chemotherapy was performed. Twenty-three years after the surgery, the tumour relapsed: the lesion was exclusively composed of mature skeletal muscle elements (diffuse and intense desmin reactivity) derived from the primary tumour as confirmed by WT1 immunoreactivity. Chemotherapy and radiotherapy have been reported previously to ablate the immature components of WT; especially, chemotherapy can modify the histological type, reducing the immature elements while leaving mature cells unaffected. We can hypothesise that both morphological and molecular features of the tumour as well as the effect of therapy can influence a tumour relapse in WT. The latter results in a high degree of differentiation and a long disease-free interval after the first diagnosis.

Autologous hematopoietic stem cell transplant with melphalan and thiotepa is safe and feasible in pediatric patients with low normalized glomerular filtration rate

Normalized glomerular filtration rate (nGFR) <60 mL/min/1.73 m(2) often precludes hematopoietic stem cell transplant (HSCT) in pediatric patients. Three patients with nGFR < 60 mL/min/1.73 m(2) enrolled on an institutional phase I trial of HSCT preparative therapy for advanced and recurrent solid tumors with escalating melphalan, ranging from 135 to 180 mg/m(2), thiotepa (600 mg/m(2)), and vincristine (2 mg/m(2)). An additional patient with low nGFR was treated with the same preparative therapy. None of the patients developed acute renal failure, excess toxicities during HSCT or delayed engraftment. These cases demonstrate that it is feasible and safe to perform HSCT in pediatric patients with low nGFR using melphalan- and thiotepa-based preparative therapy.

Survival after relapse in children with solid tumors: a follow-up study from the Italian off-therapy registry

BACKGROUND

Despite the increased survival of children with solid tumors, a significant proportion of cases still relapse following treatment discontinuation, and knowledge about the long-term outcome of this selected group of patients remains incomplete.

OBJECTIVE

To describe the long-term outcome of children treated for a solid tumor who relapsed after the elective end of therapy, and to explore factors associated with survival.

METHODS

All patients with the selected diagnoses-Hodgkin disease (HD), neuroblastoma (NB), tumor of the central nervous system (CNS), Wilms tumor (WT), or soft tissue sarcoma (STS)-enrolled in the Italian Pediatric Off-Therapy Registry in the period 1980-1998 were evaluated. Out of 3,927 patients, 694 had relapsed after treatment suspension; 639 were available for analysis. Survival and event-free survival were estimated by the Kaplan-Meier method. The log-rank test was used to assess differences in survival among the various types of cancer considered. Multivariate Cox proportional hazards analysis was adopted to explore possible prognostic factors.

RESULTS

There were 335 deaths: most of them (93%) were related to the primary cancer. The overall survival rate after relapse was 38% (95% CI 33-42) at 5 years, and 32% (95% CI 27-36%) at 15 years, while event free survival was 31% (95% CI 26-35) and 26% (95% CI 22-30%), respectively. There were significant differences according to the original diagnosis, with patients with HD doing better, and those with NB, CNS, and STS worse. No improvement of prognosis was evident over time. Post-relapse stem cell transplantation was associated with decreased risk of death only in the first year, not thereafter.

CONCLUSIONS

Overall, patients with solid tumors who relapse after treatment discontinuation have a poor outcome, but significant differences exist according to the tumor types.

Autologous stem cell transplantation for high-risk Ewing's sarcoma and other pediatric solid tumors

The prognosis for many pediatric and young adult patients with solid tumors that have metastasized at the time of diagnosis or have relapsed after therapy remains very poor. The steep dose-response curve of many of these tumors to alkylating agents makes myeloablative chemotherapy followed by autologous stem cell transplantation (ASCT) an attractive potential therapy. The role of ASCT for these high-risk patients is yet to be conclusively determined. We have transplanted 36 patients on two consecutive protocols with a variety of histological diagnoses. Overall survival (OS) was 63% (95% CI: 47-79%) at 1 year and 33% (95% CI: 16-50%) at 3 years. Patients with a diagnosis of Ewing's sarcoma (ES) or desmoplastic small round cell tumor (DSRCT) had significantly better survival than those with other diagnoses with estimated 3-year OS of 54% (95% CI: 29-79%) for this group of patients (P = 0.03). There were two transplant-related deaths both attributable to hepatic veno-occlusive disease. Median follow-up among survivors is 3.5 years (range: 0.6-7.9 years). These data justify continued investigation of ASCT as a consolidation therapy in patients with metastatic or relapsed ES and DSRCT.

Improved survival in patients with recurrent Wilms tumor: the experience of the Seoul National University Children's Hospital

The survival in cases with relapsed Wilms tumor is dismal. Recently, however the introduction of new therapeutic agents and experimental strategies has improved the survival. We analysed the survival of patients with relapsed Wilms tumor according to the treatment period. During the early period 1983-1993, patients who had received two drugs were treated with doxorubicin and the others were treated with cisplatin and etoposide, whereas during the late period 1994-2004, patients were treated with combinations of cyclophosphamide/etoposide and carboplatin/etoposide. During the early period, 8 of 57 experienced relapse, and 8 of 41 relapsed during the late period. Only 2 patients treated during the early period survived in complete response (CR), whereas during the late period, 5 patients remained alive in CR, and 3 of those received high-dose chemotherapy (HDC) with autologous peripheral stem cell rescue (SCR). The estimated 5 yr event-free survival rate was 37.5% in the entire study group, 50% for patients in the late period, and 25% for patients in the early period (p=0.38). The survival in patients with relapsed Wilms tumor dramatically improved during the late period and HDC with SCR was one of the effective salvage strategies.

Wilms' tumor: past, present and (possibly) future

Wilms' tumor is one of the successes of pediatric oncology, with an overall cure rate of over 85%, using relatively simple therapies. This excellent outcome has been the result of collaborative efforts among surgeons, pediatricians, pathologists and radiation oncologists. The results that have been achieved in children with Wilms' tumors support the strong value of the multidisciplinary team approach to cancer. The two largest cooperative groups that have studied the optimum treatment for Wilms' tumor are the National Wilms' Tumor Study group in North America and the International Society of Pediatric Oncology, involving European and other countries. The National Wilms' Tumor Study group recommends primary surgery before any adjuvant treatment, whereas the International Society of Pediatric Oncology trials are based on the use of preoperative chemotherapy. The debate on primary chemotherapy versus primary nephrectomy appears to have been overcome, in the sense that the advantages and disadvantages of these two diverse methods have emerged from large and well-performed clinical trials, and comparably low doses of anthracyclines and radiotherapy are now used. Challenges remain in identifying novel molecular, histological and clinical risk factors for stratification of treatment intensity. This could allow a safe reduction in therapy for patients known to have an excellent chance of cure with the current therapy, while identifying, at diagnosis, the minority of children at risk of relapse, who will necessitate more aggressive treatments. Another positive factor is the substantial progress that has been made in the cure for recurrent patients, with long-term survivals shifting from 30 to almost 60% in more recently treated patients with intensive-dose chemotherapy regimens. The combination of lower relapses and higher salvage rates translated into significantly improved overall survival for Wilms' tumor patients as a whole. This review covers current concepts on treatment strategies for Wilms' tumor, with an overview of the results and achievements of the important clinical trials.

Current therapy for Wilms' tumor

Wilms' tumor was the first solid malignancy in which the value of adjuvant chemotherapy was established. Multimodality treatment has resulted in a significant improvement in outcome from approximately 30% in the 1930s to more than 85% in the modern era. Although the National Wilms' Tumor Study Group and the International Society of Pediatric Oncology differ philosophically regarding the merits of preoperative chemotherapy, outcomes of patients treated with either up-front nephrectomy or preoperative chemotherapy have been excellent. The goal of current clinical trials is to reduce therapy for children with low-risk tumors, thereby avoiding acute and long-term toxicities. At the same time, current clinical trials seek to augment therapy for patients with high-risk Wilms' tumor, including those with bilateral, anaplastic, and recurrent favorable histology tumors.

Current challenges in Wilms' tumor management

Wilms' tumor is a renal cancer that predominantly affects children during the first 2 years of life. The continuing success of clinical trials in Wilms' tumor patients over the past 30 years has led to an overall survival of 85%, and treatment-related morbidity has been reduced. Less-aggressive chemotherapeutic regimes are available for patients with validated good prognostic factors, such as low stage and favorable histology. It is becoming increasingly apparent that treatment can be optimized through stratification of patients according to tumor stage and histology. Established treatments for Wilms' tumor include perioperative vincristine and actinomycin, with or without doxorubicin or radiotherapy. Relapsed patients have the option of salvage chemotherapy with ifosfamide, carboplatin and etoposide, as well as high-dose chemotherapy regimes and autologous hemopoietic stem-cell rescue. Further research is required to refine these regimes and identify further the role of additional prognostic factors in this childhood disease. In this article we discuss the most-debated issues and advances that have been made in the management of Wilms' tumor.